What is the difference between magma and lava? Help PLZ

A Magma is molten rock within the earth; lava is molten rock on the earth's surface.
B Magma is cool, lava is very hot.
Magma is very hot, lava is cool,
Magma is molten rock on the earth's surface; lava is molten rock within the earth.

An example of technology is the a. addition of a side group to an organic molecule during synthesis. b. use of a new antibiotic to fight an infection. c. measurement of iron concentration in a water sample. d. study of atomic fusion reactions

Nitric oxide (no) can be formed from nitrogen, hydrogen and oxygen in two steps. in the first step, nitrogen and hydrogen react to form ammonia: n2(g) + 2 h_2(g) rightarrow 2 nh_3 (g) delta h = -92. kj in the second step, ammonia and oxygen react to form nitric oxide and water: 4 nh_3(g) + 5 o_2(g) rightarrow 4no(g) + 6 h_2o(g) delta h = -905. kj calculate the net change in enthalpy for the formation of one mole of nitric oxide from nitrogen, hydrogen and oxygen from these reactions. round your answer to the nearest .

Different isotopes indicate that an element will have different numbers of