Unit 0

Question 1

What is a chemical symbol?

Answer 1

A one or two letter representation of an element.

Question 2

What is an average atomic mass?

Answer 2

The weighted average mass of the isotopes of that element.

Question 3

What is an atomic number?

Answer 3

The number of protons in an atom.

Question 4

What is a mass number?

Answer 4

The sum of the number of neutrons and protons in an atomic nucleus.

Question 5

What are groups/families? Why are they grouped this way?

Answer 5

Vertical columns on the periodic table. Families are sorted by their valence electrons (outer shell electrons).

Question 6

What is Group 1 on the periodic table?

Answer 6

Alkali Metals

Question 7

What is Group 2 on the periodic table?

Answer 7

Alkaline Earth Metals

Question 8

What are Groups 3-12 on the periodic table?

Answer 8

Transition Metals

Question 9

What is Group 16 on the periodic table?

Answer 9

Chalcogens

Question 10

What is Group 17 on the periodic table?

Answer 10

Halogens

Question 11

What is Group 18 on the periodic table?

Answer 11

Noble Gases

Question 12

What are periods?

Answer 12

Horizontal rows on the periodic table.

Question 13

What is a nuclear symbol?

Answer 13

A set of values relating to the element’s data. (The superscript indicates the mass number and the subscript indicates the atomic number.)

Question 14

What is an isotope symbol?

Answer 14

The chemical name + neutrons and protons added together.

i.g. Oxygen-16

Question 15

What is an ion?

Answer 15

An atom or group of atoms that has a positive or negative charge.

Question 16

What is an isotope?

Answer 16

Atoms of the same element that have different numbers of neutrons.

Question 17

What is a subscript?

Answer 17

A number written slightly below and to the right of a chemical symbol that shows how many atoms of an element are in a compound.

Question 18

What is a coefficient?

Answer 18

The number written in front of a reactant or product.

Question 19

What is an ionic bond? What do they transfer?

Answer 19

A chemical bond that is formed from a metal and a nonmetal. Ionic bonds transfer electrons.

Question 20

List the steps for writing formulas for ionic bonds.

Answer 20

1. Find the charge of the metal and write in to the top right-hand corner of the symbol for the metal.
2. Find the charge of the nonmetal and write it to the top right-hand corner of the nonmetal.
3. Crisscross the charges.
   * The oxidation number for the metal becomes the subscript for the nonmetal and vice versa.
   * Do NOT write 1’s and always reduce to the simplest ratio.
   (i. g. Be^+2 and S^-2 = BeS)

Question 21

List the steps for writing the name for an ionic bond.

Answer 21

1. Write the name of the metal first.
2. Write the name of the nonmetal.
3. Change the ending of the nonmetal to ‘ide’.
   (i. g. NaCl = Sodium Chloride)

Question 22

What is an oxidation number?

Answer 22

The charge of an element. (Can be positive or negative.)

Question 23

What are the oxidation numbers for each family on the periodic table?

Answer 23

Alkali Metals: +1
Alkaline Earth Metals: +2
Transition Metals: No set oxidation numbers. (Exceptions being Ag = +1 and Zn = +2.)
Boron Family: +3
Carbon Family: +4/-4
Nitrogen Family: -3
Chalcogens: -2
Halogens: -1
Noble Gases: 0

Question 24

What is a covalent bond? What do they share?

Answer 24

A chemical bond between two nonmetals. Covalent bonds share electrons.

Question 25

Name the greek prefixes for numbers 1-10.

Answer 25

``` 1 = Mono 2 = Di 3 = Tri 4 = Tetra 5 = Penta 6 = Hexa 7 = Hepta 8 = Octa 9 = Nona 10 = Deca ```

Question 26

List the steps for writing the name of a covalent bond.

Answer 26

1. Write the prefix for the number associated with the first element (unless it's number is 1). 2. Write the full name of the first element. 3. Write the prefix for the number associated with the second element. 4. Write the name of the second element and change its ending to 'ide'. (i. g. CO2 = Carbon Dioxide)

Question 27

Describe how to count atoms.

Answer 27

- Count the subscripts for each element. - Multiply the coefficient (if there is one) to each subscript following it. - Distribute subscripts on the outside of parenthesis (if there are any).

Question 28

What are polyatomic ions?

Answer 28

Ionic bonds within formulas with more than two elements. Each polyatomic bond has its own separate charge apart from its elements.

Question 29

Describe how to write formulas and names for ionic bonds with transition metals.

Answer 29

To find the formula, crisscross the charges (given and found). (i.g. Cobalt (III) Oxide = Co2O3) To write the name, uncross the charges and give the appropriate roman numeral for the subscript of the first element. (i.g. Fe2O = Iron (I) Oxide)

Question 30

What is the purpose of using significant figures?

Answer 30

With significant figures, we can show how precise a number is. If we express a number beyond the place to which we have actually measured (and are therefore certain of), we compromise the integrity of what this number is representing.

Question 31

What are the rules for counting significant figures?

Answer 31

1. All non-zero digits are significant. (i.g. 2.738 has 4 sig figs.) 2. All zeroes between two non-zero digits are significant. (i.g. 3.002 has 4 sig figs.) 3. Any zeroes at the beginning of a number with a decimal point are non-significant. (i.g. 0.00807 has 3 sig figs, since the first three zeroes are non-significant.) 4. Trailing zeroes in a number without a decimal point are non-significant. (i.g. 12300 has 3 sig figs, since the last two zeroes are non-significant.) 5. The trailing zeroes in a number with a decimal point are significant. (i.g. 3.800 has 4 sig figs.) 6. A change of units displayed does not change the number of significant figures in a measurement.

Question 32

What is the equation for finding density?

Answer 32

D = m/V * D = Density * m = Mass * V = Volume