Answer:
Mass of Oxygen = 32 grams
Explanation:
Given:
Mass of water = 36 grams
Mass of Hydrogen = 4 grams
Find:
Mass of Oxygen
Computation:
Using Law of Conservation of mass
Mass of water = Mass of Hydrogen + Mass of Oxygen
36 grams = 4 grams + Mass of Oxygen
Mass of Oxygen = 32 grams
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:
mental model is an explanation of someone's thought process about how something works in the real world. It is a representation of the surrounding world, the relationships between its various parts and a person's intuitive perception about his or her own acts and their consequences. Mental models can help shape behaviour and set an approach to solving problems (similar to a personal algorithm) and doing tasks.
:)
I wrote the answer on this paper and here is the calculations step by step
very sry the "V" must be replaced with 285 and the 285 must be replaced with "V" and the answer is 231.09 cm3. sorry for the inconvenience.