Question

complete the table; the first two rows have been done for you. use your table to complete the rest.
lithium: symbol li, protons 3, neutrons 7 - 3 = 4, electrons 3
carbon: symbol c, protons 6, neutrons 12 - 6 = 6, electrons 6
sodium: symbol na, protons 11, neutrons 14 - 3 = 11
aluminum: symbol al, protons 13
lead: symbol pb, protons 82
titanium: symbol ti, protons 22
zinc: symbol zn, protons 30
mercury: symbol hg, neutrons 80, electrons 17
tungsten

Explanation:

Step1: Recall the properties of atoms

In a neutral atom, the number of protons is equal to the number of electrons. The mass number (not given here, but for the purpose of finding neutrons if we assume standard isotopes, for example, sodium has a common isotope with mass number 23, so neutrons = 23 - 11 = 12. But since the first two rows use a pattern (maybe assume atomic number for protons and electrons, and for neutrons, if we consider that for lithium atomic number 3, mass number 7 (7 - 3 = 4 neutrons), carbon atomic number 6, mass number 12 (12 - 6 = 6 neutrons). So for sodium (atomic number 11), electrons = 11, neutrons (if we assume mass number 23) 23 - 11 = 12. For aluminum (atomic number 13), electrons = 13, neutrons (assuming mass number 27) 27 - 13 = 14. For lead (Pb, atomic number 82), electrons = 82, neutrons (assuming mass number 207) 207 - 82 = 125. For titanium (Ti, atomic number 22), electrons = 22, neutrons (assuming mass number 48) 48 - 22 = 26. For zinc (Zn, atomic number 30), electrons = 30, neutrons (assuming mass number 65) 65 - 30 = 35. For mercury (Hg, atomic number 80), electrons = 80, neutrons (assuming mass number 200) 200 - 80 = 120. For tungsten (atomic number 74), symbol W, protons = 74, neutrons (assuming mass number 184) 184 - 74 = 110, electrons = 74.

Answer:

Element	Symbol	Protons	Neutrons	Electrons
Carbon	C	6	6	6
Sodium	Na	11	12	11
Aluminum	Al	13	14	13
Lead	Pb	82	125	82
Titanium	Ti	22	26	22
Zinc	Zn	30	35	30
Mercury	Hg	80	120	80
Tungsten	W	74	110	74