4th Period: Potassium and Calcium—Electrons go into the fourth energy level. A small piece of sodium metal is placed in water. The sodium reacts with the water and gets very hot, producing sodium ...

The modern periodic table is based closely on the ideas he used ... all have the same kind of reaction with water. The group of elements below were grouped together because they tended to combine ...

Students look more deeply into the structure of the atom and play a game to better understand the relationship between protons, neutrons, electrons, and energy levels in atoms and their location in ...

That is because about 60 per cent of our body consists of water (H2O), which is made of ... These are almost one-quarter of the periodic table and are mainly found in the first four periods.

The modern periodic table is based closely on the ideas he used ... all have the same kind of reaction with water. The group of elements below were grouped together because they tended to combine ...