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:
An atom is the basic building block of matter. Anything that has a mass-- in other words, anything that occupies space--is composed of atoms.
Answer:
Explanation:
Some signs of a chemical change are a change in color and the formation of bubbles. The five conditions of chemical change: color chage, formation of a precipitate, formation of a gas, odor change, temperature change. Or Light is given off, a permanent color change occurs, gas is given off, heat is given off, and a precipitate is formed
Answer A
x-ray optical telescope.
hope this helps!.
Answer:
A-Shape
C-state
Explanation:
reactivity and flammability are both indicators of chemicals changes
