An earthquake's magnitude is a measure of how much energy an earthquake releases. Typically, the richter scale is used.
F = ma = (kg)(m/s2) = kg ´ m/s2 N
hope this helps :D
They have same chemical properties
for example the elements of group VIII are called noble gases .They are unreactive, odorless and colorless.
Cs -137 has a half life of about 30 years. If 60 years pass, there is two half lives passed so 1/2 * 1/2= 1/4. Take 1/4 and multiply it with the mass given:
(1/4)*20mg=5mg left
