The answer is D. When heated, there is only physical process not chemical process. So the mass of the gas will not change. When heated, according to the thermal expansion, the volume will increase. And the mass is constant, so the density will decrease. Density=Mass/Volume.
The answer to this question would be: 3.125%
Half-life is the time needed for a radioactive molecule to decay half of its mass. In this case, the strontium-89 is already gone past 5 half lives. Then, the percentage of the mass left after 5 half-lives should be:
100%*(1/2^5)= 100%/32=3..125%
A physical process is a process which do not change the substance structure only its shape or phase is changed. On the other hand, a chemical process involves the formation of new substances.
a. corrosion of aluminum metal = chemical process
b. Melting of ice = physical process
c. Pulverizing an aspirin. = physical processd. Digesting a candy bar. = chemical process
e. Explosion of nitroglycerin. = chemical process
f. Milk turning sour. = chemical process
g. Burning of paper. = chemical process
h. Forming of frost on a cold night. = physical process
i. Bleaching of hair with hydrogen peroxide. = chemical process
j. A copper wire is hammered flat. <span>= physical process</span>
Answer:
Ratio is 4:1
Explanation:
from graham's law of gaseous diffusion:
but Ra = 2Rb:
The instrument is a Geiger counter and is used to measure radioactive level around people's bodies.
