Answer:Half-life is the amount of time it takes for the initial mass of the isotope to decompose, by half, into other lighter atoms.
Explanation:Different radioactive isotopes have different half-lives. For example, the element technetium-99m has a half life of 6 hours. This means that is 100 kg of the element is left to decay, in 6 hours, 50kg of the mass will have changed into other elements/atoms. The half-life of uranium-238 is 4.5 billion years while that of polonium-216 is only 0.145 seconds.
Answer:
Speed at which it will reach the ground is given as

Total time for which it will remain in air is given as
t = 6.3 s
Explanation:
As we know that the object is projected upwards with speed


now when it will reach the ground then we have

so we have


so we have

Now speed of the object when it reaches the ground is given as



<span>B) Both soap brands out perform hand sanitizer in killing bacteria.</span>
Looking at the data, the conclusion is pretty obvious, the two different types of soap resulted in about half the bacteria cultures as either the hand sanitizer, or just using warm water. In fact, the hand sanitizer looks like it's even worse than simply using warm water. So looking at the four available options, the best choice is "B) Both soap brands out perform hand sanitizer in killing bacteria."
Answer:
D. Checking to see if the brake fluid is contaminated
Explanation: