Answer:
25g
Explanation:
Given parameters:
Half life of X = 5days
Mass of sample of radioactive elements = 100g
The half-life of a radioactive material is the time it takes for a sample to decay by half. At the half-life, an original sample would have yielded equal daughter to parent ratio.
At time (days) Mass of sample
0 100g
5 50g
10 25g
Every 5 days, the sample will split into half.
Therefore, 25g will remain after 10days.
Answer : The number of half-life periods will be, 3
Explanation : Given,
Initial amount of lead = 10 kg
Amount of lead after decay = 1.25 kg
Half-life = 22 years
Formula used :

where,
a = amount of reactant left after n-half lives
= Initial amount of the reactant
n = number of half lives
= half-life
Now put all the given values in the above formula, we get:




Thus, the number of half-life periods will be, 3
Answer:
It is found that W1 - W2 loss in weight of solid when immersed in water is equal to the weight of the water displaced by the body. This verifies Archimedes' principle.
Answer:
b
Explanation:
it loses energy due to friction because if it hits objects the objects slow it down and which causes it to start slowing down
2.low orbit because any satellite in low orbit will encounter some of earths atmosphere it will slow down a bit and fall into a lower orbit