You might owe that gold necklace around your neck to a moody, long-dead star from the universe’s ancient past. According to a ...

Chemistry: Elements, Compounds, and Mixtures (2nd Edition) (1983) is a 20-minute educational film from the *Chemistry Series* ...

There are over one hundred different elements and these are all made of atoms. Presenter: OK. Well, before we get into this further, let's check out the top things to know about all of this.

In Bohr’s model, if an electron orbit is not already filled, then it’s easier for the atoms to exchange or share those ...

Their "failure" was, in retrospect, important evidence for the existence both of heavy water and of isotopes—atoms of an element that have the same number of protons but a different number of ...

Heavy actinides—elements at the bottom of the periodic table, after plutonium—are radioactive, rare and chemically complex, ...

There are over one hundred different elements and these are all made of atoms. Presenter: OK. Well, before we get into this further, let's check out the top things to know about all of this.