When was the periodic table created ?

Some familiar products contain some of the same types of atoms. for instance, the chemical formula for baking soda is nahco 3. the chemical formula for liquid bleach is naclo, and the chemical formula for table salt is nacl. which choice best describes why these three products have some of the same types of atoms in common?

What is the enthalpy of combustion (per mole) of c4h10 (g)? –2,657.5 kj/mol –5315.0 kj/mol –509.7 kj/mol –254.8 kj/mol

Ireally need ! calcium metal reacts with a potassium chloride solution to form calcium chloride and potassium ions. balance this reaction. (s) + (aq) → cacl2(s) + +(aq) a) 1, 2, 1, 2 b) 1, 2, 1, 1 c) 1, 1, 1, 1 d) 2, 1, 2, 1