Step-by-step explanation:
An atom is stable if the forces among the particles that makeup the nucleus are balanced
So it’s 4 + 21 - 18
So it’s 7
Answer:
(3;4); (-3;-4); (3;-4); (-3;4)
Step-by-step explanation:
for more information see the attached picture.
Answer:
missing terms are -2,3,8
Step-by-step explanation:
-7, ?, ?, ?, 13
To find missing terms we add last two term and divide it by 2
so that we will get middle term

so sequence becomes
-7, ?, 3, ?, 13
Again we add -7 and 3 and then divide it by 2 to get middle number

so sequence becomes
-7, -2, 3, ?, 13
Again we add 3 and 13 and then divide it by 2 to get middle number

-7, -2, 3, 8, 13
So, missing terms are -2,3,8
Answer:
Step-by-step explanation: