Chapter 2

Question 1

What subatomic particles are in the nucleus of an atom?

Answer 1

1) protons

2) neutrons

Question 2

How are electrons arranged?

Answer 2

Around the nucleus in shells

Question 3

What is the mass of an electron?

Answer 3

1/1836th the mass of a proton

Question 4

What is the mass of a proton + neutron?

Answer 4

1

Question 5

Where is most of the mass of an atom?

Answer 5

In the nucleus

Question 6

What is the overall charge of an atom?

Answer 6

1) zero

2) neutral

Question 7

How does the periodic table list elements?

Answer 7

In order of protons in the nucleus

Question 8

What is atomic number, A?

Answer 8

Number of protons

Question 9

What are isotopes?

Answer 9

Atoms of the same element with different numbers of neutrons + different masses

Question 10

What is mass number, Z?

Answer 10

Number of protons + number of neutrons

Question 11

How does the number of neutrons affect the reactions of an element?

Answer 11

They have no effect

Question 12

What is an ion?

Answer 12

1) charged atom

2) number of electrons different to number of protons

Question 13

What are cations?

Answer 13

1) atoms with fewer electrons than protons

2) overall positive charge

Question 14

What are anions?

Answer 14

1) atoms with more electrons than protons

2) overall negative charge

Question 15

What is the mass of a carbon-12 isotope?

Answer 15

12 atomic mass units (12u)

Question 16

What is relative isotopic mass?

Answer 16

The mass of an isotope relative to 1/12th of the mass of an atom of carbon-12

Question 17

What is relative atomic mass?

Answer 17

The weighted mean mass of an atom of an element relative to 1/12th of the mass of an atom of carbon-12

Question 18

What does weighted mean mass take into account?

Answer 18

1) percentage abundance of each isotope

2) relative atomic mass of each isotope

Question 19

How can you find the percentage abundance of the isotopes in a sample of an element?

Answer 19

Mass spectometry

Question 20

What is the method of mass spectometry?

Answer 20

1) sample placed in mass spectrometer
2) sample vaporised + ionised to form positive ions
3) ions accelerated. heavier ions move slower + more difficult to deflect than lighter ions - ions of each isotope separated
4) ions detected on mass spectrum as mass-to-charge ratio - greater the abundance, larger the signal

Question 21

mass-to-charge ratio (m/z) =

Answer 21

relative mass of ion / relative charge of ion

Question 22

What type of ions do atoms of metals on the left of the periodic table form?

Answer 22

cations

Question 23

What type of ions do atoms of non-metals on the right of the periodic table form?

Answer 23

anions

Question 24

What is a binary compound?

Answer 24

A compound containing 2 elements only

Question 25

How do you name a binary compound?

Answer 25

1) use name of first element

2) add second element but change ending to -ide

Question 26

What is a polyatomic ion?

Answer 26

An ion containing atoms of more than one element bonded together

Question 27

What is the charge of NH4?

Answer 27

1+ (NH4+)

Question 28

What is the charge of OH?

Answer 28

1- (OH-)

Question 29

What is the charge of NO3?

Answer 29

1- (NO3-)

Question 30

What is the charge of CO3?

Answer 30

2- (CO3 2-)

Question 31

What is the charge of SO4?

Answer 31

2- (SO4 2-)

Question 32

What conditions are true in the correct formula of an ionic compound?

Answer 32

1) overall charge = zero

2) sum of positive charges = sum of negative charges

Question 33

What is a diatomic molecule?

Answer 33

Two atoms bonded together

Question 34

What elements exist as small molecules?

Answer 34

1) P₄

2) S₈