It should have 10 electrons
Half life is the time taken by a radioactive isotope to decay by half its original mass. In this case, the halflife of the radioactive isotope is 5000 years.
Initially the mass is 100 %; thus the mass that will be left will be given by;
New mass = Original mass × (1/2)^n where n is the number of half lives;
n = 10000/5000 = 2
New mass = 100% ×(1/2)^2
= 100 % × 1/4
= 25%
Therefore; the mass left after 10000 years is 25% or 1/4 of the original mass.
Answer: ^_^
Explanation:
its because during day time the ball becomes heated up and the air inside it try to come out as the heat air always try to go up swelling up the ball,
so in the evening when the air cools down the ball too cools down and air inside it also cools down making the ball feel soft,
Therefore, a football feels hard on a hot day but feels softer in the evening
Hope it helped u,
pls mark as the brainliest
^_^
