Answer: half life
Explanation: Radioactive decay follows first order kinetics and the time required for the decay of a radioactive material is calculated as follows:

t= time required
k= disintegration constant
x= amount of substance left after time t
a= initial amount of substance
when one half of the sample is decayed, one half of the sample remains and t can be represented as 
at
, 


Answer:
B. it is a community of plants,animals and there physical surrounding.
The stoichiometric ratio of CuCl2 to NaCl is 1 is to 2. The stoichiometric ratio of 31.0 g CuCl2 is 26.95 grams of NaCl by converting the amount of CuCl2 to mole and multiplying by 0.5 and molar mass of NaCl.This amount is equal to 78.65% yield.
The object and description that matches is Object 2 and T.
Object 1 has no matching description.
<h3>Fish Aquarium Filter </h3>
A Fish aquarium filter is a filter whose function is to clean the water of debris, removes the toxic buildup of ammonia and nitrates, and aerates the water so that fish can in a conducive environment and breathe properly
<h3>Engine Oil Filter</h3>
An engine oil filter is a filter whose function is to filter and remove contaminants that may be present in the engine oil, transmission oil, lubricating oil, or hydraulic oil in order for proper functioning of the engine.
Therefore, the object and description that matches is Object 2 and T.
Object 1 has no matching description.
Learn more about filters and their uses at: brainly.com/question/10719424
Answer:
hello,
first one is 25.15
second is 301.55
Explanation:
honestly if you look up on the internet there is a converter to get you your answers