The atoms in the diagram above are... sharing pairs of valence electrons.

losing valence electrons.

transferring valence electrons.

pooling valence electrons.

The following reaction shows sodium carbonate reacting with calcium hydroxide. na2co3 + ca(oh)2 → naoh + caco3 how many grams of naoh are produced from 20.0 grams of na2co3? (molar mass of na = 22.989 g/mol, c = 12.01 g/mol, o = 15.999 g/mol, ca = 40.078 g/mol, h = 1.008 g/mol) 12.2 grams 15.1 grams 24.4 grams 30.2 grams

Use examples from the article to explain one positive and one negative effect that chemistry has had on society.

To find the enthalpy of a reaction in the lab, you measured the of the reactants and the change during the reaction.