Unit 2 4:2The Structure Of Atoms

Question 1

How many protons does each element have?

Answer 1

Each element has a unique # of protons

Question 2

Unreacted Atoms

Answer 2

Have no overall charge- because there is an equal # of protons and electrons, the charge cancels out

Question 3

Electric Force

Answer 3

Holds atoms together.

+protons are attracted to -protons by the electric force.

Question 4

Atomic # equals

Answer 4

of protons

Question 5

of protons equals

Answer 5

Atomic #

Question 6

What do atoms of an element have in common with other atoms of the same element?

Answer 6

Atoms of each element have the same # of protons, but they can have different # of neutrons

Question 7

Mass #

Answer 7

The sum of the numbers of protons and neutrons in the nucleus of an atom
(Total number of subatomic particles in the nucleus)

Question 8

Calculation for # of neutrons

Answer 8

Mass number - atomic number = Number of neutrons

Question 9

Why do isotopes of the same element have different atomic masses?

Answer 9

Isotopes of an element vary in mass because their numbers of neutrons differ.
(Some isotopes are more common that others)

Question 10

Radioisotopes

Answer 10

Unstable isotopes that emit radiation and decay into other isotopes

Question 11

What unit is used to express atomic mass?

Answer 11

Unified atomic mass units -
A unit of mass that describes the mass of an atom or molecule, it is exactly 1 1/2 the mass of a carbon atom with mass number 12
(Symbol, u)

Question 12

Mole

Answer 12

•useful for counting small particles
The SI base unit used to measure the amount of a substance whose number of particles is the same as the number of atoms of carbon in exactly 12 g of carbon-12
(Abbreviation, mol)

Question 13

1 mol =

Answer 13

602,213, 670,000,000,000,000,000 particles
Written as 6.022 x 10^23
(Avogadro’s number)

Question 14

What other unit are moles related to?

Answer 14

Grams

Question 15

Molar mass

Answer 15

The mass in grams of one mile of a substance

Ex.
1 mol of carbon-12 atoms has a mad of 12.00 g, so the molar mass of carbon-12 is 12.00 g/mol

Question 16

What other unit can moles convert between?

Answer 16

Grams

Question 17

How do you find the molar mass of a compound?

Answer 17

Add up the molar masses of all of the atoms in a molecule of the compound

Ex. Finding the molar mass of water, H2O
Molar mass of O= 16.00 g/mol
Molar mass of H= 1.01 g/mol
Molar mass of H2O= (2 x 1.01 g/mol) + 16.00 g/mol = 18.02 g/mol

Question 18

What are protons, neutrons and electrons distinguished by?

Answer 18

Mass
Charge
Location in the atom