If the unstable atoms in a rock have a half-life of 2 million years and the rock begins with 8 mg of unstable atoms, how many milligrams of unstable atoms will be found in the rock 4 million years after its formation? A.8 mg
B.4 mg
C.2 mg
D.1 mg

they both go up but then go back down. they both end lower than they started. lastly, they both are competitive/the second on.

explanation:

oxygen = 21% of the atmosphere

nitrogen = 78%

carbon dioxide = 0.1%

argon =0.934%

the correct answer is - d. china has a large and growing population.

the fact that china has a large (the biggest) population, and it is still growing, doesn't hinder the agriculture production in the country. in fact, it can for increased production in the agriculture, since there's more labor force, as well the sheer mass of people produces lots of scientists that come up with new inventions as to how to improve this sector. nice example is the inner mongolia region in china, in general dominated by the gobi desert, but few scientist came up with a nice idea as to how to make the region productive by using plants that are very resistant to droughts, so lots of people have been employed, and the region is becoming greener and greener each year, and the production of food in this region is also increasing.

its temperature is increasing. this causes molecular vibrations to increase.