# Chemistry

## Chapter Two, Section One

Section one was mainly about measurements and units. Measurements and units are used daily on signs for example. Miles and kilometers are two different measurements, the united states mostly uses miles. Not all measurements are exact but scientist like for them to be. A base unit is a defined unit in a system of measurement that is based on an object or event in the physical world. There are seven base units and they are basically a defined unit in a system of measurement. There is time, length, and mass. Then we get to derived units. A Derived unit is a unit that is defined by a combination of base units. There is also volume, density, and temperature. (Density= Mass/Volume)

## Section 2.2-2.4

Section 2.2 was about scientific notation & dimensional analysis. Scientific notation is an easy way to write big and small numbers. And dimensional analysis is a method of problem that focuses on the units used to describe matter. In scientific notation, you use addition, subtraction, multiplication, and division. When adding and subtracting numbers using scientific notation, the exponents have to be the same before you do the work. When you use multiplication, you multiply first factors then add exponents. When you divide, divide first factors & subtract the exponent of division from exponent of dividend. Then you have your conversion factor. A conversion factor is a compansion of equal values used to express the same quantity in different units. Accuracy and precision refers to how close measured value is to accepted value.

## Chapter Three

Chapter Three Was Mainly About Matter And Properties. Matter Is Generally Considered To Be Anything That Has Mass And Takes Up Space. There Is A Variety Of Properties Included In Chapter Three, Some Example Would Be: Physical Property, Chemical Property, Properties Of Matter, Changes In Matter, Mixtures Of Matter, Elements, And Compounds.

## The TEKS

The TEKS Are Objectives To Help You. You Use The TEKS For Information You Need And It Helps When Your Using The Book, You Can Use The TEKS Too. Also It Is A General Requirement. Students Will Be Awarded With One Credit For Successful Completion On This Course. Here Are The Required Prerequisites: One Unit Of High School Science And Algebra I.

## TEKS For Chapter 2

2.1) Units Of Measurements. TEKS- (2.F)

2.2) Scientific Notation & Dimensional Analysis. TEKS- (2.G)

2.3) How Reliable Are Measurements? TEKS- (2.F)

2.4) Representing Data. TEKS- (2.H) (2.I)

## TEKS For Chapter 3

3.1) Properties Of Matter. TEKS (4.C) (4.A)

3.2) Changes In Matter. TEKS- (4.A) (8.D)

3.3) Mixtures Of Matter. TEKS- (4.D)

3.4)Elements & Compounds. TEKS- (5.B) (5.A) (6.D)