Essay on chem lecture

Submitted By slathsri
Words: 683
Pages: 3

September 3, 2013

What is Chemistry?

Chemistry is the study of matter and its interaction with other matter and energy.

What is Energy?
It is either light or Heat ( it can interacts w types of matter; absorbed or released)

What is Matter?
It is something with mass and also something that takes up space.

Matter can be broken down into pure substance or mixture.

(Insert Diagram 1 from notebook here)

Units
Meters (m)
Kg – mass
Moles- amount of something mol=6.02x10 somthings (number of anything in a mole… ex. Number or student per mole) – Number of atoms of Carbon in one mole
Seconds- Time (s)
Temperature (K- Kelvin)
L- Volume =0.001m3
J= k*gm3/s2

Conservations

Current x _Desired/ Currents_= Desired Units

Ex. 1.00x102g Hg 13.6g/L

(Insert Converstion from notebook here)

Sig Figs- keep track of how precise your measurement is..

(Insert Sig Figs Example here)

Rules of Sig Figs:
1. Any non zero digit is significant
2. Any zero in between integers is significant
3. Leading zeros- 0.0003.. Not Significant (so all the four 0’s)
4. Trailing zeroes- if there is a decimal point all of the zeroes are significant- ex. 100.00; If it without a decimal point then it is not significant. Ex. 100

100- 1 sig fig BUT 1.0x102 – is also 100 but has 2 sig figs
1.00000x102 – has 6 sig figs

635- has 3 sig figs… (The precision happened in the highlighted digit)

6350- has 3 sig figs

635.00- has 5 sig figs… (The precision happened in the highlighted digit)

Ex. 0.00001234 – There is a decimal point and then there are zeroes but it does not start off with an integer so there are only 4 sig figs which are 1234. Ift it was 10.00001234 there will be 10 sig figs.

For Multiplication or Division- answer has same number of sig figs as the FEWEST in your calculations

(Insert example from notebook here)

For addition and subtraction : answer will match with the fewest decimals from your calculation.

(Insert Example from notebook here)

If you have multiplication/division and addition/ subtraction in one problem.. you combine the rules.

(Insert Example here)

September 5, 2013

The power of a scientific theory-

One or more well established hypotheses may form the basis for a scientific theory. A scientific theory is a model for the way nature is and tries to explain not merely what nature does but why. As such, well established theories are the pinnacle of scientific knowledge often prediction behavior far beyond the observations or laws from which they were developed.

Clicker Problem 1:
You weigh 2.30g of ammonia on one scale and 1.325g on another scale. Knowing that the density of ammonia is 0.8235g/cm^3, whats your volume? Use sig…