Answer:
Check the explanation
Step-by-step explanation:
1)
Atomic number of Se = 34
So, number of proton = 34
use:
charge = number of proton - number of electron
-2 = 34 - number of electron
number of electron = 36
number of neutron = mass number - atomic number
= 78 - 34
= 44
Answer:
44
34
36
2)
number of proton = mass number - number of neutron
= 65 - 36
= 29
29 is atomic number for Cu
use:
charge = number of proton - number of electron
+1 = 29 - number of electron
number of electron = 28
Answer:
Cu
29
28
3)
Atomic number is 36 for Kr
use:
charge = number of proton - number of electron
= 36 - 36
= 0
use:
mass number = number of proton + number of neutron
= 36 + 42
= 78
Answer:
Kr
78
0