One of the first things that you'll come across in the subject of Chemistry is the Mole.
It can be thought of as a type of unit that tells you how much of a chemical substance there is. A mole simplifies the way that chemicals are counted and makes them easy to compare to each other. You will always hear your teacher say "convert to moles" and
it's usually the first step to most chemistry problems.
The main thing that the mole is used to express is the number of molecules. A mole will always contain exactly 6.02x10^23 molecules - which is Avogadro's number. This tells you that no matter if I'm talking about water, or hydrogen, or lead, or helium --
a mole of any of these chemical substances will always contain 6.02x10^23 molecules.
It's kind of like saying a "dozen". A dozen of eggs or oranges or apples will always contain exactly 12 of those things. It does not matter what you are talking about, how big or heavy those items but using the word...
One of the most mind boggling parts of physics is the very first section - involving projectile motion and the 4 kinematics equations. These equations assume that there is constant acceleration, given by the acceleration of gravity which is the g constant
you see in the formulas (9.8 m/s^2).
When an object moves through the air (and ignoring the effects of air resistance), it moves in two dimensions - an X and a Y component. The first step is to separate the X and Y, meaning - you can apply those 4 formulas to the X direction (horizontally)
and you can also apply them in the Y-direction (vertically).
Imagine if you throw a ball sideways off the cliff that is 3m high, and you want to know how long it takes.
Since both of the x and y parts are happening at the same time, that means that the Time that you use for both equations is the same. This means conceptually - that if I shot something straight sideways across a field with, let's say, a cannon, it would
Today's blog post is about fractions. Fractions can be a little tricky when you first learn them.
Fractions are made of two numbers, a numerator on top and denominator on the bottom. The best way to think of a fraction is like pieces of pie. So if you divide a pie into 12 *equal* size pieces, and you decide you want 3 pieces, then your fraction is 3/12.
A fraction is similar to a percent. The only difference is that a percent always has 100 as the denominator. Other than that, a percent is just like a fraction with some number of pieces that you are taking out of the 100 total pieces.
In the same example above, if you had divided the pie into 100 equal pieces instead, and you decide you want 3 pieces again, then your fraction is now 3/100 or 3%.
Fractions can only be compared when the denominators are equal. I can compare 3/8 with 5/8 but I cannot compare 3/8 with 4/12 because the bottom number is different. To compare two fractions, then you...
I mentioned the idea of using mnemonics in my last blog post. Mnemonics are a very effective memorization technique.
They help you to remember a list of items. Often, you can also use mnemonics to remember the order of the items. Basically, you take the first letter of each item in your list and put them altogether to make a sentence or phrase that is easier to remember.
Some teachers say it is a crutch, but I say use whatever works! Even years later, your mind might go blank trying to tighten or untighten a screw but then you can use "Righty-tighty, lefty-loosey” and you'll know which way to turn it.
I researched a few common mnemonics that might come in handy as you progress through your academic career.
Algebra/Math: FOIL method. FOIL method is used in Algebra and means to do the First, Outside, Inside, and Last. When you have two binomial algebraic expressions such as (2x+3y)(5x-7y), you want to multiply the first (2x and 5x), outside (2x and -7y), inside...
Lately, I've been tutoring for the TAKS, aka the Texas Assessment of Knowledge and Skills. In Texas, students are required to take the TAKS exam before their Senior year in order to pass high school. This can be a real roadblock sometimes, especially when
there is one section that may be difficult for you, (i.e., Math). The first thing to do is review the results of your last test. Were there some sections that you did more poorly than the others? Once you've identified your weak areas, THAT is where you want
to "concentrate your firepower" and put most of your time and effort.
Go buy test prep books at Amazon.com or your local Barnes & Noble bookstore. You can also download the old tests from the Texas Education Agency for practice: http://www.tea.state.tx.us/index3.aspx?id=3839&menu_id=793. Print these out and write on them.
The concepts do not change very much and there are only so many ways to write a test question.
Next thing you want to do is...