Click for money

Wednesday, January 8, 2014

This Day in Science History - January 9 - Richard Abegg

January 9th is Richard Abegg's birthday. Abegg was a German chemist who was one of the early researchers of valence theory. His experiments showed a tendency between maximum of minimum valence levels of elements differed usually by a value of eight. This relationship became known as Abegg's rule when Gilbert Lewis proposed his octet rules. Abegg was also an avid enthusiast of ballooning. This hobby would ultimately cause his death when he flew his balloon with an engineer and female relative. When the balloon encountered strong winds, they opened the gas valves to cause the balloon to descend. It reached the ground safely and the other two were able to exit the basket. Abegg was caught as a gust of wind as he exited and was crushed by the basket.

What Judges Look for in Science Fair Projects

First off, I found this great list of all of the science fairs in the world that have webpages. The list gets updated regularly. It is organized according to subject and geographical location. So... if you don't know where to find a science fair, start there. Once you find a science fair, you'll want to make the most of your experience. Good grades and prizes are nice, too. I've written about project ideas, but you also need to think about what judges will look for when it comes to rating your project. Here's a quick rundown: •Did you use the scientific method? Experiments and designs that solve a problem will get higher ratings than models or demonstrations. •Could you explain your project without reading it off of your display? Basically this shows that you actually did your project as opposed to getting too much help from a parent or teacher. •Did you seem friendly? Were you interested in and excited about your project? Enthusiasm and a willingness to answer questions can really help your presentation. •Was your poster attractive? Posters that are easy to read and visually appealing will do better than anything handwritten and blotched by water stains. If it looks like you made your poster on the bus on the way in, don't expect it to win a prize or get a good grade.

Shelf Life of Common Household Chemicals

You can tell when milk is bad and you probably have an idea of when to throw out the mayo in your fridge, but you may be unaware of the shelf life of other common household chemicals. For example, did you know hydrogen peroxide is only good for about a month once you've opened it? Gas which contains ethanol is at its best for only a few weeks
Some common everyday chemicals last indefinitely, but others have a shelf life. This is a table of expiration dates for several household chemicals. In some cases, the chemicals have a shelf life because the product accumulates bacteria or breaks down into other chemicals, rendering it ineffective or potentially dangerous. In other cases, the expiration date is related to diminished effectiveness over time. Expiration Dates for Common Chemicals Chemical Expiration Date air freshener spray 2 years antifreeze, mixed 1 to 5 years antifreeze, concentrated indefintely baking powder unopened, indefinitely if properly stored opened, test by mixing with water baking soda unopened, indefinitely if properly stored opened, test by mixing with vinegar batteries, alkaline 7 years batteries, lithium 10 years bath gel 3 years bath oil 1 year bleach 3 to 6 months conditioner 2 to 3 years dish detergent, liquid or powder 1 year fire extinguisher, rechargeable service or replace every 6 years fire extinguisher, nonrechargeable 12 years furniture polish 2 years gasoline, no ethanol several years, if properly stored gasoline, with ethanol from date of manufacture, 90 days in your gas tank, about a month (2-6 weeks) honey indefinitely hydrogen peroxide unopened, at least one year opened, 30-45 days laundry detergent, liquid or powder unopened, 9 months to 1 year opened, 6 months metal polish (copper, brass, silver) at least 3 years Miracle Gro, liquid unopened, indefinitely opened, 3 to 8 years motor oil unopened, 2 to 5 years opened, 3 months Mr. Clean 2 years paint unopened, up to 10 years opened, 2 to 5 years soap, bar 18 months to 3 years spray paint 2 to 3 years vinegar 3-1/2 years Windex 2 years

This Day in Science History - January 8 - Melvin Calvin and Dark Reactions

January 8th marks the passing of Melvin Calvin. Calvin was an American biochemist who discovered what would become referred to as the "Calvin cycle" or carbon fixation in photosynthesis. The Calvin cycle deals with the part of photosynthesis that is called dark reactions. A more accurate description would be light-independent reactions. These reactions don't require light to progress like most photosynthesis reactions and can occur either day or night. They take place in the stroma of the chloroplast and convert carbon dioxide into sugar using ATP and NADPH.

Easy Crystal Growing

These crystals are easy to grow, only take a few hours, and don't require boiling water or harmful chemicals. Perfect, right? All you need is a cup, Epsom salts, and hot tap water. In the cup, stir together equal amounts of Epsom salts and hot tap water (you can microwave the water for 45 seconds to a minute if you prefer, but don't boil it). If you want colored crystals, add a few drops of food coloring. Set the cup in the refrigerator to cool, undisturbed, for at least a couple of hours. Drain off the water and this is what you'll have. If you like, you can slide the crystals out of the cup and set them on a paper towel to dry and keep.

Atoms bond chemically to form molecules.

Types of bonding
The periodic table is organized in columns, called groups or families, and rows, called periods.  There are several groups or periods that have specific names.
Bond type Happens between Electrons are
Ionic Metal & non-metal Transferred
Covalent Non-metals Shared
Polar Covalent Non-metals Shared unevenly
Metallic Metals pooled
There are general characteristics of each type of bonding:
  • Ionic: High melting points, most dissolve in water, conduct electricity when dissolved in water, brittle
  • Covalent: Low melting points, most do not dissolve in water, do not conduct electricity when dissolved in water
  • Polar covalent: Medium melting points, some dissolve in water, do not conduct electricity when dissolved in water
  • Metallic:  Soft, conduct heat and electricity, do not dissolve in water
Bond Polarity
When nonmetals bond covalently with a large difference in electronegativity, a polar bond is formed.  A polar bond has a partial separation of charges.  Polar bonds are symbolized with an arrow pointing towards the more electronegative element and a crossed tail by the less electronegative element

Valence Shell Bonding Theory
The Valence Shell Bonding Theory assumes that bonds are formed when atomic orbitals overlap.  Direct overlap leads to sigma bonds and parallel overlap leads to pi bond. 


Organic Chemistry Rapid Learning Series

Organic chemistry is mostly about one element - carbon. The diversity in its valence and connectivity leads to millions of organic compounds and thousands of organic reactions. It is overwhelming if you adapt a brute force and rote memorization approach. Focus on the fundamentals such as electronic structures, nomenclatures, stereo chemistry, reactions and mechanisms, the learning will flow. These are the exact skills you will learn from this series.

Atomic and Molecular Structure
The number of protons is equal to the atomic number. The number of neutrons is equal to the mass number minus the atomic number. The number of electrons is equal to protons, if neutral. From the number of electrons, determine the electronic configuration, following the arrow from the bottom. The s orbital has two electrons; the p orbital has six electrons; the d orbital has ten electrons; and the f orbital has fourteen electrons. The valence electrons are the number of electrons in the outer shell.   Isotopes have the same number of protons, but a different number of neutrons.  Ions have lost or gained electrons.  Cations have lost electrons.  Anions have gained electrons.  Radicals have no loss or gain of electrons and have a single electron. Lewis structures are drawn using the valence electrons. Formal charge = [number of valence electrons] B [nonbinding electrons] - 0.5 [bonding electrons].

Tuesday, January 7, 2014

৫৩১ শিক্ষাপ্রতিষ্ঠানে আগুন দিয়েছে দুর্বৃত্তরা: শিক্ষামন্ত্রী

দশম জাতীয় সংসদ নির্বাচন প্রতিরোধের নামে ৫৩১টি শিক্ষাপ্রতিষ্ঠানে দুর্বৃত্তরা আগুন দিয়েছে। আজ মঙ্গলবার রাজধানীর দক্ষিণখানের ফায়েদাবাদ সরকারি প্রাথমিক বিদ্যালয় পরিদর্শনকালে শিক্ষামন্ত্রী নুরুল ইসলাম নাহিদ সাংবাদিকদের একথা বলেন।
মন্ত্রী জানান, প্রাথমিক হিসাব অনুযায়ী সারা দেশে ৪১৯টি প্রাথমিক বিদ্যালয়, ৮২টি মাধ্যমিক বিদ্যালয়, ২১টি মাদ্রাসা ও নয়টি কলেজ ক্ষতিগ্রস্ত হয়েছে। এ বিষয়ে বিস্তারিত তথ্য সংগ্রহের পর শিগগিরই তা খতিয়ে দেখে এসব শিক্ষাপ্রতিষ্ঠান মেরামত, সংস্কার বা নির্মাণের ব্যবস্থা নেওয়া হবে। শিক্ষার্থীদের পড়ালেখা যাতে কোনোভাবেই ক্ষতিগ্রস্ত না হয়, সেদিকে নজর দেওয়ার জন্য নির্দেশনা দেওয়া হয়েছে বলেও জানান।
নির্বাচন প্রতিরোধের নামে শিক্ষাপ্রতিষ্ঠান জ্বালিয়ে-পুড়িয়ে সভ্যতাবিনাশী অপকর্ম এ দেশের আন্দোলন-সংগ্রামের ইতিহাসে একটি জঘন্য নজির বলে মন্তব্য করেন শিক্ষামন্ত্রী। তিনি বলেন, ‘এ ধরনের জঘন্য, বর্বরোচিত অমানবিক হামলা দেশের শিক্ষা ব্যবস্থাকে পরিকল্পিতভাবে ধ্বংস করে দেওয়ার অপচেষ্টা।’
শিক্ষামন্ত্রী বলেন, ‘বিএনপির প্রত্যক্ষ সহযোগিতায় স্বাধীনতাবিরোধী জামায়াত-শিবির একাত্তরের পরাজয়ের প্রতিশোধ নিতে আন্দোলনের আড়ালে সন্ত্রাস ও নাশকতা চালাচ্ছে।’

যুক্তরাষ্ট্রে বিপজ্জনক শীত, ঘরে থাকার পরামর্শ

যুক্তরাষ্ট্রজুড়ে লাখ লাখ মানুষ তীব্র শীত মোকাবিলার শেষ প্রস্তুতি নিতে ব্যস্ত। মেরু আবর্তের প্রভাবে ওই দেশে তাপমাত্রা দুই দশকের মধ্যে সর্বনিম্ন পর্যায়ে নেমে যাওয়ার পূর্বাভাস দেওয়া হয়েছে।
কানাডার কয়েকটি অঞ্চল ও যুক্তরাষ্ট্রের উত্তর-পূর্বাঞ্চলে চলতি বছরের শুরু থেকেই শূন্যের নিচে তাপমাত্রা বিরাজ করছে। এসব এলাকায় ইতিমধ্যে বড় ধরনের তুষারপাত ও শৈত্যপ্রবাহের কারণে দুই ফুট পুরু তুষারের স্তর পড়েছে। এই দুর্যোগে গত বুধবার থেকে এ পর্যন্ত ১৬ জন প্রাণ হারিয়েছে। এ ছাড়া বাতিল করা হয়েছে উড়োজাহাজের অন্তত তিন হাজার ৭০০টি ফ্লাইট। বিভিন্ন অঞ্চলে শিক্ষাপ্রতিষ্ঠান বন্ধ করে দেওয়া হয়েছে। আর স্থানীয় লোকজনকে খাবারের মজুদসহ ঘরের ভেতরে অবস্থানের পরামর্শ দেওয়া হয়েছে।
শৈত্যপ্রবাহ যুক্তরাষ্ট্রের মধ্য-পশ্চিমাঞ্চলের দিকে এগিয়ে যেতে শুরু করেছে। এতে দক্ষিণাঞ্চলীয় টেনেসি ও অ্যালাবামা অঙ্গরাজ্যও হুমকির মুখে পড়েছে। মিনেসোটা ও নর্থ ডাকোটা অঙ্গরাজ্যেও স্মরণকালের সবচেয়ে খারাপ আবহাওয়া বিরাজ করতে পারে। ‘বিপজ্জনক’ ঠান্ডা থেকে

যুক্তরাষ্ট্রে প্রচণ্ড শীতে চারজনের মৃত্যু

মেরু আবর্তের প্রভাবে যুক্তরাষ্ট্রের বিস্তৃত মধ্যাঞ্চলের তাপমাত্রা গতকাল সোমবার গত দুই দশকের মধ্যে সর্বনিম্ন পর্যায়ে নেমে গেছে। অন্তত চারজনের প্রাণহানির খবর পাওয়া গেছে। কানাডার কয়েকটি অঞ্চলেও একই পরিস্থিতি বিরাজ করছে।
বার্তা সংস্থা রয়টার্সের প্রতিবেদনে জানানো হয়, বিপজ্জনক শীতের প্রভাবে যুক্তরাষ্ট্রের সংশ্লিষ্ট অঞ্চলের শিক্ষাপ্রতিষ্ঠান, ব্যবসা-বাণিজ্য বন্ধ হয়ে গেছে। উড়োজাহাজের কয়েক হাজার ফ্লাইট বাতিল করা হয়েছে।
বিবিসি অনলাইনে প্রকাশিত প্রতিবেদনে জানানো হয়, যুক্তরাষ্ট্রের উত্তর-পূর্বাঞ্চল ও কানাডার সংশ্লিষ্ট অঞ্চলে ইতিমধ্যে বড় ধরনের তুষারপাত ও শৈত্যপ্রবাহের কারণে দুই ফুট পুরু তুষারের স্তর পড়েছে। গতকাল তিন হাজার ৭০০ ফ্লাইট বাতিল করা হয়েছে। স্থানীয় লোকজনকে খাবারের মজুতসহ ঘরের ভেতরে অবস্থানের পরামর্শ দেওয়া হয়েছে। বাস্তুহারাদের আশ্রয় শিবিরগুলোর ধারণক্ষমতা ছাড়িয়ে গেছে।
এবারের ব্যতিক্রমী তীব্র ঠান্ডার কারণ হিসেবে সুমেরু অঞ্চল থেকে প্রবাহিত বিশেষ ধরনের আবর্তকে দায়ী করা হচ্ছে। ঘড়ির কাঁটার বিপরীতমুখী ওই শৈত্যপ্রবাহ এবং বাতাসের সমন্বয়ে তৈরি আবর্তটির কারণে যুক্তরাষ্ট্রের উত্তর ও মধ্যাঞ্চলে তাপমাত্রা মাইনাস ৫১ ডিগ্রি সেলসিয়াসে নেমে যায়।
যুক্তরাষ্ট্রের জাতীয় আবহাওয়া বিভাগ সূত্র জানায়, মধ্য-পশ্চিমাঞ্চল থেকে শুরু করে মধ্য-আটলান্টিক অঞ্চল দিয়ে গত কয়েক বছরে সবচেয়ে তীব্র শৈত্যপ্রবাহ শুরু হয়েছে। ওহাইও, সাউথ ডাকোটা ও ইলিনয় অঙ্গরাজ্যে ওই প্রবল শীত জেঁকে বসবে। এ ছাড়া টেনেসি ও কেন্টাকি অঙ্গরাজ্যেও কয়েক ইঞ্চি পুরু তুষার পড়তে পারে।

বোকামি অচিরেই টের পাবে বিএনপি: ওবায়দুল কাদের


আওয়ামী লীগের সভাপতিমণ্ডলীর সদস্য ও যোগাযোগমন্ত্রী ওবায়দুল কাদের বলেছেন, দশম জাতীয় সংসদ নির্বাচন মিস করে বিএনপি যে বোকামি করেছে, অচিরেই সেটা টের পাবে। দশম সংসদ নির্বাচনের শিডিউল দেওয়ার আর সুযোগ নেই।
আজ মঙ্গলবার দুপুরে বঙ্গবন্ধু অ্যাভিনিউয়ে আওয়ামী লীগের কেন্দ্রীয় কার্যালয়ে ঢাকা মহানগর আওয়ামী লীগের বর্ধিত সভায় তিনি এসব কথা বলেন। ১০ জানুয়ারি দুপুর দুইটায় রাজধানীর সোহরাওয়ার্দী উদ্যানে অনুষ্ঠেয় আওয়ামী লীগের জনসভা সফল করতে এই বর্ধিত সভা করা হয়।
যোগাযোগমন্ত্রী বলেন, এবার একাদশ নির্বাচনের শিডিউল ঘোষণা করা হবে। এজন্য আলাপ-আলোচনা হতে পারে। তবে বিরোধী দলকে সব নাশকতা ও সহিংসতা পরিহার করতে হবে। নয় তো সরকার হার্ডলাইনে যেতে বাধ্য হবে।
ওবায়দুল কাদের বলেন, গত পাঁচ বছরে বিরোধী দলের আন্দোলন দেখে মনে হয়েছে তারা আর আন্দোলন জমাতে পারবে না। সুতরাং দশম সংসদ নির্বাচনের শিডিউল নিয়ে আন্দোলন করে লাভ নেই।
মন্ত্রী বলেন, দশম সংসদ নির্বাচন করতে দলের যেসব নেতা-কর্মী নিরলসভাবে কাজ করেছেন, তাঁদের দল ও সরকারে যথাযথ মূল্যায়ন করা হবে। দলকে চাঙা করতে কিছু কঠিন সিদ্ধান্ত নেওয়া হবে বলে জানান তিনি।
ঢাকা মহানগর আওয়ামী লীগের সহসভাপতি ফয়েজউদ্দিন মিয়ার সভাপতিত্বে এই বর্ধিত সভায় আরও বক্তব্য দেন আওয়ামী লীগের যুগ্ম সাধারণ সম্পাদক জাহাঙ্গীর কবীর নানক, আইন প্রতিমন্ত্রী কামরুল ইসলাম, ঢাকা মহানগর আওয়ামী লীগের সাধারণ সম্পাদক মোফাজ্জল হোসেন চৌধুরী মায়া প্রমুখ।

Violence unacceptable: UN chief

Mother, son murdered in Barisal

Monica Mridha, 65 and Sushil Mridha, 45 were found murdered in their own home at Christianpara of the Upazila’s Deghergoti village around 11:30am on Tuesday.

Monica’s other son Somiron Mridha, 40 is missing since the recovery.

Police said the mother and her two sons used to live in the house.

Halima Begum, a local in the village, said she called out for Sushil after she saw their door shut while she was passing by the house.
 She peeped through the ventilator of the one-storey building and began screaming when she saw the floor covered in blood.

BCS finishes with perhaps best championship yet

This may have been the best game yet, and now we have to say goodbye.
It’s been fun and controversial and maddening and wrong, but Monday night was so very right.
There were three lead changes in the fourth quarter bewteen Florida State and Auburn to provide an overabundance of drama.
It was a heart-stopping, show-stopping, heck of a way to end the Bowl Championship Series era.
Who would’ve thought we’d be left wanting anything more from the BCS other than kicking it on its way out the door?
This was the perfect ending to a tumultous era.
Florida State rallied from an 18-point, first-half deficit beat Auburn 34-31 and remain undefeated.
Hesiman Trophy winner Jamies Winston went from hot mess to hero, engineering his two-minute offense for the winning 2-yard touchdown pass to Kelvin Benjamin with 13 seconds left.
The Seminoles had 79 seconds left on the clock to start that drive.
Winston finally delivered after he’d fumbled and stumbled and crumbled under the pressure of Auburn’s fast and physical defense earlier.

Senior Moments: Cleaning up the new year

I’m not going to tell you what you should or shouldn’t do,” I said to my husband, in a slightly exasperated tone.
“Why not?” he asked. “Don’t you love me anymore?”
All right. After 27 years, perhaps there is a slight tendency on some people’s parts (and, yes, I might be one of these people) to sometimes gently suggest to a partner a better or more efficient way to do something. Like actually putting the new toilet paper roll in the holder rather than balancing it on top of the empty one, thereby turning it into a moving target for the next user.
And where is the harm if I like my pancakes silver-dollar-sized and request that he use a teaspoon rather than a tablespoon when making mine? Or asking the king of fluffy waffles (from scratch) to confine the flour to the bowl and not the floor?

How to Supercool Water

You can cool water below its usual freezing point and then crystallize it into ice on command. This is known as supercooling. These are step-by-step instructions for supercooling water at home. All you need is water and either a freezer or some ice.

Supercooling Water - Method #1

The simplest way to supercool water is to chill it in the freezer.
  1. Place an unopened bottle of distilled or purified water in the freezer.
  2. Allow the bottle of water to chill, undisturbed, for about 2-1/2 hours. The exact time needed to supercool the water varies depending on the temperature of your freezer. One way to tell your water is supercooled is to put a bottle of tap water (impure water) into the freezer with the bottle of pure water. When the tap water freezes, the pure water is supercooled. If the pure water also freezes, you either waited too long, somehow disturbed the container, or else the water was insufficiently pure.
  3. Carefully remove the supercooled water from the freezer.

The Ultimate Chemistry Kit

You know those cool toys you wanted as a kid, but didn't get? A chemistry kit falls into this category for me. Oh, I have picked up several small, specialized kits, for slime and crystals and volcanoes, but never the classic test tube, beakers, and blowing-up-the-kitchen-with-chemicals sort of kit. Why? Well, for one, we all know I'm perfectly capable of causing mayhem without an actual kit. Then there is the expense. Have you priced chemistry kits? They are cheaper than picking up glassware and chemicals separately, but not low-budget. Finally, most modern chemistry kits lack... well... chemicals.

Fire Extinguisher Science Project

It's easy to make a homemade fire extinguisher using kitchen materials. One common type of fire extinguisher uses carbon dioxide to starve the fire of oxygen. You can generate this gas from any of several chemical reactions and make a simple unit to disperse the gas. This makes a great science project! Kick it up a notch by applying the Ideal Gas Law to maximize the distance you can spray the CO2. You can manipulate the volume of the container, temperature of the ingredients or amount of gas that is produced in order to change the characteristics of the fire extinguisher.

Can You Eat Snow?

Just about every kid who has ever seen snow has tried to catch a snowflake on her tongue and every good snowball fight involves a healthy, albeit involuntary mouthful of snow. Yet, it's a different matter if you're considering ingesting large quantities of the white stuff. Have you ever wondered whether it's safe to eat snow in ice cream or melt it to drink?... Find out

Periodic Table Trends and Periodicity Quiz

Do you understand how the periodic table is organized and how you can use it to predict trends or periodicity in the properties of the elements? You can be sure you'll be tested on these concepts if you're taking a chemistry class, so how about a little review? Here's a 10-question multiple choice quiz that covers element trends and tests your ability to predict how the properties of the elements are affected by their position in the periodic table... Take the quiz

This Day in Science History - January 7 - Eilhard Mitscherlich

January 7th is Eilhard Mitscherlich's birthday. Mitscherlich was a German chemist who introduced the idea of isomorphism. He theorized that chemical substances that crystallize together into a solid will typically have similar chemical formulas. Isomorph compounds can substitute each other when crystallizing and the shape of the crystal will not change. Another property of isomorphic compounds concerns the relative sizes and positions of the ions and cations of the minerals. Isomorphic minerals will have the same coordination and relative ion sizes of each component.

Teach Yourself Chemistry

Learn the Basic Concepts

Chemistry is a logical science. You can master the essential concepts yourself. You can study these concepts in any order, but it's probably best to start from the top and work your way down, since many concepts build on understanding units, conversion and how atoms and molecules interact.

Introduction to Chemistry: Learn about what chemistry is, what chemists do, and why you would want to study this science.
Units & Measurements: Get a handle on the metric system and the commom units used in chemistry.
The Scientific Method: Scientists, including chemists, are systematic about the way they study the world. Find out how to use the scientific method to collect data and design experiments.
The Elements: Elements are a basic building block of matter. Learn what an element is and get facts for them.
The Periodic Table: The Periodic Table is a way elements can be organized, based on their similar properties. Find out what that table is, how it was designed, and how you can use it to make your study of chemistry much easier.
Atoms and Ions: Atoms are single units of an element. Ions can be made up of one or more types of elements and carry an electrical charge. Learn about the parts of an atom and how to identify the different types of ions.
Molecules, Compounds, & Moles: Atoms can be joined together to make molecules and compounds. A mole is a useful way of measuring an amount of atoms or larger components of matter. Define these terms and learn how to perform calculations to express quantities.
Chemical Formulas: Atoms and ions don't bond together randomly. Find out how to predict how many of one type of atom or ion will combine with others. Learn to name compounds.
Chemical Reactions & Equations: Just as atoms and ions combine in very specific ways, molecules and compounds react with each other in definite quantities. Learn how to tell whether or not a reaction can occur and what the products of a reaction will be. Write balanced chemical equations to describe reactions.
Thermochemistry: Chemistry is the study of both matter and energy. Once you learn to balance the atoms and charge in a chemical reaction, you can examine the energy of the reaction as well.
Electronic Structure: Electrons are found in regions around the nucleus of an atom. Learning about the structure of the electron shell or electron cloud is important for understanding how atoms and ions will form bonds.
Chemical Bonds: The atoms in a molecule or compound are attracted and repelled with respect to each other in ways that determine the types of bonds they can form.
Molecular Structure: Once you understand the types of bonds that can be formed between components in a substance, you can begin to predict and understand how molecules are formed and the shapes they take.
Liquids & Gases: Liquids and gases are phases of matter with properties distinctly different from the solid form. Collectively, liquids and solids are termed fluids. The study of fluids and how they interact is important for understanding the properties of matter and predicting the ways in which that matter can react.
Rates of Reaction: Several factors affect how quickly and completely a reaction proceeds. Learn about these factors and how to calculate the speed at which a reaction can occur.
Acids & Bases: There are several ways to define acids and bases. One way is to look at hydrogen ion concentration. No matter which method you choose, these categories of chemicals participate in some very important reactions. Learn about acids, bases, and pH.
Oxidation & Reduction: Oxidation and reduction reactions go hand in hand, which is why they are also called redox reactions. Acids and bases may be thought of as reactions involving hydrogen, or protons, while redox reactions tend to be concerned with electron gain and loss.
Nuclear Reactions: Most chemical reactions involve exchanges of electrons or atoms. Nuclear reactions are concerned with what happens inside the nucleus of an atom. This includes radioactive decay, fission, and fusion.

 

অধ্যায় - ৫ রাসায়নিক বন্ধন

অধ্যায় - ৫ রাসায়নিক বন্ধন ১. কোন গ্রুপের অধাতু আয়নিক বন্ধন গঠন করে? ক) ১৩ ও ১৬ খ) ১৫ ও ১৭ গ) ১৬ ও ১৭ ঘ) ১৭ ও ১৮ সঠিক উত্তর:...

Popular posts