atomic number and mass number

Question 1

what does the small number on a chemical symbol represent?

Answer 1

the atomic number

Question 2

what does the large number on a chemical symbol represent?

Answer 2

the mass number

Question 3

what does an atomic number tell us?

Answer 3

the number of protons in an atom of an element

Question 4

how many protons is in one atom of lithium?
how many electrons?
how many neutrons?
7
Li 
3

Answer 4

3 protons
3 electrons
4 neutron

Question 5

the number of electrons are equal to the number of…

Answer 5

protons

Question 6

what does the mass number tell us?

Answer 6

the total of protons and neutrons added together

Question 7

how do we calculate the number of neutrons in an atom of an element

Answer 7

mass number - atomic number

Question 8

what are the number of protons neutrons and electrons in an atom of
9
Be
4

Answer 8

protons = 4
electrons =4
neutrons =5

Question 9

what are the number of protons neutrons and electrons in an atom of
19
F
9

Answer 9

protons = 9
electrons =9
neutrons =10

Question 10

what are the number of protons neutrons and electrons in an atom of
23
Na
11

Answer 10

protons =11
electrons =11
neutrons =12

Question 11

what are the number of protons neutrons and electrons in an atom of
31
P
15

Answer 11

protons =15
electrons =15
neutrons =16

Question 12

what do we call it when some atoms of an element contain a different number of neutrons?

Answer 12

an isotope

Question 13

what are isotopes?

Answer 13

atoms of an element with different numbers of neutrons

Question 14

all atoms of an element have the same number of…

Answer 14

protons

Question 15

carbon has 3 common isotopes
a)12.      b)13.     c)14
    C.           C.          C
    6.           6.          6
calculate their protons electrons and neutrons

Answer 15

a) 6 protons 6 electrons 6 neutrons
b) 6 protons 6 electrons 7 neutrons
c) 6 protons 6 electrons 8 neutrons

Question 16

the 2 most common types of chlorine are
a)
35
Cl
17
b)
37
Cl
17
calculate the number of protons neutrons and electrons in each isotope

Answer 16

a) 17 protons 17 electrons 18 neutrons

b) 17 protons 17 electrons 20 neutrons

Question 17

what are ions?

Answer 17

atoms which have an overall charge.

they have either gained or lost electrons

Question 18

ions that have lost electrons are..

Answer 18

positive

Question 19

ions that have gained electrons are…

Answer 19

negative

Question 20

ions with a single positive charge means they have…

Answer 20

lost one electron

Question 21

a) ions with 2 negative charges means they have…

b) ions with 2 positive charges means they have…

Answer 21

a) gained 2 electrons

b) lost 2 electrons

Question 22

calculate the number of protons neutrons and electrons in an atom of this oxygen ion
16
O 2-
8

Answer 22

protons= 8
neutrons =8
electrons = 10
8 + 2 electrons gained = 10

Question 23

calculate the number of protons neutrons and electrons in an atom of this aluminium ion
27
Al 3+
13

Answer 23

has lost 3 electrons so
electrons=10
protons = 13
neutrons=14