Answer:
18 groups are in the modern periodic table
Answer:
C. Planet D has the greatest mass and will exert a greater gravitational force
Answer:
They were produced by stars that lived and died before our solar system was born.
Explanation:
According to what it's understood today, all elements heavier than hydrogen (including helium and excluding some that were created in laboratories) are created through nuclear fusion in the core of stars.
They start fusing hydrogen into helium, then as the star grows older helium is fused into beryllium and so on for all the periodic table.
So as far as science understands it today it's a literal truth that we are made of stars. (as almost everything else)
Answer:
C. It is radiation leftover from the Big Bang
Answer:
Density is the amount of mass in a specified space. It is a way to measure how compact an object is
Explanation:
