CHM 1

How is the Periodic Table of Elements (PTOE) arranged?

The PTOE shows all of the known elements arranged by increasing atomic number


The smallest particle of an element:

is an individual atom


Diatomic molecules and examples:

Elements tha exist as two atoms joined together

Examples: Br2, I2, N2, Cl2, H2, O2, F2

(All are gases except Br2 is a liquid)

 

Matter
Anything that has mass and takes up space.
(includes air!)
Pure substance
Has only one type of particle
2 types of pure substances

1. Element: has only 1 type of atom (Silver (Ag); Oxygen O2

2. Compound has different types of atoms joined together (H20, NaCl)

Temperature
measure of the average kinetic energy of the particles in a sample of matter
Units of Temperature

° C or K

Celsius to Kelvin

Formula to convert Celsius to Kelvin (°C to K)
K = °C + 273
Volume
Amount of space occupied by a substance
what units can volume be measured in?
L=liters, mL=milliliters, or cm3=cubic centimeters
Density
Mass per unit of volume

D= mass/volume=g/mL

Molar mass (MM)
Represents the mass of 1 mole of a substance
(for single elements the MM=the atomic mass)

Units=g/mol

1 mole =
6.02 X 1023 particles/atoms (Avogadro’s number)
What is the density of an object with a mass of 2.34 and a volume of 7.3 mL?

D = m/v

; ; = 2.34 g / 7.3 mL

; ; = 2.34 ;;0.32 g/mL

; ; = 0.32g/mL

;

What group contains the noble gases?
Group 18
What group contains the Alkali Metals?
Group 1
What Group contains Alkaline Earth Metals?
Group 2
What group contains the Halogens?
Group 17
List the 3 main classifications of elements
metals, non-metals, and metalloids
What element is in group 13, period 3
Al
What element is in group 2, period 4?
Ca
Identify the group and the period for the element S (Sulfur)
Group 16, period 3
What element has the atomic number 12?
Mg
What is the molar mass for the element Cl?
35 g/mol
What is the molar mass for H2O?

H: ;2 x 1g/mol= 2g/mol

O: ;1 x 16 g/mol = 16 g/mol

;

So the MM = 18 g/mol

How many atoms are found in calcium phosphate Ca3(PO4)2;
13
What is the molar mass of CH3CH2CH3

H: ;8 x 1 = 8 g/mol

C: ; 3 x 12 = 26 g/mol

;

MM = 32 g/mol

List how many of each atom in the compound Al(NO3)3

Al – 1

N – 3

O – 9

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How can you identify the IV and the DV from a title?

The effect of the IV on the DV

;

Ex. ;The effect of increasing temperature on the solubility of sugar;

IV; temperature (what you will change)

DV: solubility of sugar (measure how much dissolved)