1st Quarter Chemistry 2012: Counting Particles

Protons, Neutrons, and Electrons Practice Worksheet

Fill in the blanks in the following worksheet.  Please keep in mind that the isotope represented by each space may NOT be the most common isotope or the one closest in atomic mass to the value on the periodic table.

Atomic symbol	Atomic number	Protons	Neutrons	Electrons	Atomic mass
B			6
	11				24
		31	37
				39	89
	29		35
		43			100
Pb					207
			102	70
		89			225
Mo			53
	81				206
	100		159
No					261
Yb					172
		106	159

Solutions for the Protons, Neutrons, and Electrons Practice Worksheet:

Atomic symbol	Atomic number	Protons	Neutrons	Electrons	Atomic mass
B	5	5	6	5	11
Na	11	11	13	11	24
Ga	31	31	37	31	68
Y	39	39	50	39	89
Cu	29	29	35	29	64
Tc	43	43	57	43	100
Pb	82	82	125	82	207
Yb	70	70	102	70	172
Ac	89	89	136	89	225
Mo	42	42	53	42	95
Tl	81	81	125	81	206
Fm	100	100	159	100	259
No	102	102	159	102	261
Yb	70	70	101	70	172
Sg	106	106	159	106	265