Balancing Practice (some of these may be in the simulation)
Balance the following equations. You may find it useful to use scratch paper to write how many atoms of each element you have on both sides of the reaction.

16. P4(s) + F2(g) → PF3(s)

17. ___C(s) + H2O(g) → CH4(g) + CO2(g)

18. HgO(s)→ O2(g) + Hg(l)

19. CaCO3(s) → CO2(g) + CaO(s)

see below

Explanation:

16. 1 P₄(s) + 6 F₂(g) → 1 PF₃(s)

17. 2 C(s) + 2 H₂O(g) → 1 CH₄(g) + 1 CO₂(g)

18. 2 HgO(s)→ 1 O₂(g) + 2 Hg(l)

19. 1 CaCO₃(s) → 1 CO₂(g) + 1 CaO(s)

why do the isotopes of a particular element behave differently in nuclear reactions but the same in chemical reactions? chemical reactions involve changes to electrons in an atom; isotopes do not differ in electrons, and so they react the same way during chemical changes.

the number of protons in the nucleus of a given element. has slight luster and conducts electricity at high temperatures like metal.but like a nonmetal,boron is brittle and does not conduct electricity well at low temperatures. in graphite, carbon is a soft,brittle solid.it is reflective,ductile,or malleable.