1. How do we know that elements are made in different types of stars?

Stars create new elements in their cores by squeezing elements together in a process called nuclear fusion. First, stars fuse hydrogen atoms into helium. Helium atoms then fuse to create beryllium, and so on, until fusion in the star's core has created every element up to iron.

Explanation:

Almost all of the elements in the universe originated in the high-pressure hearts of stars or during a star's violent death. But some elements are not "star stuff." Hydrogen and helium trace their lineage back to the big bang. Other elements, like francium and plutonium, are only produced in trace amounts by the decay of uranium—and by trace amounts, I mean that if you gathered all the naturally occurring plutonium in the world, you'd have roughly 0.05 grams of it.

Explanation: youre welcome :)

explanation:

metals have excess of electrons whereas non-metals have deficiency of electrons. thus, in order to gain stability metals easily donate their electrons to the non-metals.

for example, electronic configuration of sodium is and electronic configuration of phosphorous is .

when a phosphorous atom and sodium atom combine together then sodium will donate is extra one electron to the phosphorous atom. as a result there will be formation of ionic bond between sodium and phosphorous.

the reaction will be as follows.

there, are three sodium sodium atoms and each of them will donate its one extra electron to phosphorous atom. thus, the sub-shell of phosphorous gets completely filled.  

thus, we can conclude that electrons are transferred from atoms of sodium to atoms of phosphorous. this transfer makes the sodium atoms donate one electron and the phosphorous atoms to gain one electron. as a result, the sodium and phosphorus atoms strongly attract each other.