How many of valence electrons do the elements in column 4 have? Are these elements very reactive? Explain your answer.

When the water vapor cools it condenses select a number that represents his process on the

Sally is making a model of a magnesium atom with an atomic mass number of 24 for her chemistry class. she has foam balls for the protons, neutrons, and electrons. she has added 6 neutrons to her model so far. how many more neutrons does she need to add to complete her neutral atom of magnesium?

Which of the following is a physical change? a.burning a piece of wood b.sawing a piece of wood in half c.rust forming on an iron fence d.a copper roof changing color from orange to green