Help, please this is a science task, and I need to explain what’s the difference between expansion and contraction (please don’t paste the answers your gonna put here) (it has to be your own words) the first person to help me will get)

The compound formed from 2 atoms of hydrogen and one atom of oxygen is

Match the vocabulary terms to their definitions. 1 . a long, chain-like set of molecules made up of repeating units joined end to end polymer 2 . a hard, brittle, heat- and corrosion-resistant material made by subjecting a nonmetallic mineral mixture to intense heat ceramic 3 . a plastic with low elongations that cannot be recycled thermoset 4 . a carbon fiber embedded in a polymer resin matrix thermoplastic 5 . a plastic with high elongations that can be recycled crystal 6 . a solid form resulting from the arrangement of atoms, ions, or molecules in definite geometric patterns composite

Asolubility table shows that almost all compounds of group 1 metals are soluble in water. this general rule tells you that mgi2 is soluble rbno3 is soluble cacl2 is soluble co2 is soluble