4.1 Parts of an Atom

Question 1

proton’s role

Answer 1

determines the identity of the atom

Question 2

neutron’s role

Answer 2

holds together the nucleus

Question 3

electron’s role

Answer 3

responsible for reactivity

Question 4

proton’s charge

Answer 4

+1

Question 5

neutron’s charge

Answer 5

0

Question 6

electron’s charge

Answer 6

-1

Question 7

proton’s mass

Answer 7

1 amu

Question 8

electron’s mass

Answer 8

almost zero

Question 9

neutron’s mass

Answer 9

1 amu

Question 10

proton’s location

Answer 10

nucleus (proton)

Question 11

neutron’s location

Answer 11

nucleus (neutron)

Question 12

electron’s location

Answer 12

outside nucleus

Question 13

most of the mass of the atom

Answer 13

comes from the nucleus

Question 14

protons + neutrons

Answer 14

= mass number

Question 15

the number of protons is also

Answer 15

the atomic number of an element

Question 16

of protons - # of electrons

Answer 16

= charge

Question 17

why don’t protons stick together?

Answer 17

they each have a +1 charge

Question 18

why can’t an atom lose or gain a proton?

Answer 18

would change the identity of the atom

Question 19

what is in the space between electrons?

Answer 19

nothing
empty space

Question 20

when are atoms unstable?

Answer 20

when they have more or less neutrons or electrons than protons

Question 21

what is a valence electron?

Answer 21

electrons in the outermost shell of an atom

Question 22

what is most of the volume of an atom?

Answer 22

empty space outside the nucleus

Question 23

An atom has 4 protons, 6 neutrons, and 5 electrons.
What is it’s charge?

Answer 23

it’s charge is -1

Question 24

An atom has 4 protons, 6 neutrons, and 5 electrons.
What is it’s mass number?

Answer 24

mass number: 10

Question 25

An atom has 4 protons, 6 neutrons, and 5 electrons.
What is it’s atomic number?

Answer 25

atomic number: 4

Question 26

An atom has 4 protons, 6 neutrons, and 5 electrons.
How many valence electrons does it have?

Answer 26

3 valence electrons

Question 27

what are isotopes?

Answer 27

atoms with the same number of protons but different numbers of neutrons

Question 28

isotopes have the same atomic number but different

Answer 28

masses

Question 29

isotopes react

Answer 29

similarly in chemical reactions

Question 30

isotopes are often

Answer 30

unstable/radioactive