Question

1. give the symbol and number of neutrons in one atom of: (to get “mass number”, you must round the “atomic mass” to the nearest whole number) show your calculations. barium carbon fluorine europium bismuth hydrogen magnesium mercury name the element which has the following numbers of particles:

Explanation:

Step1: Recall element symbols

Barium - Ba, Carbon - C, Fluorine - F, Europium - Eu, Bismuth - Bi, Hydrogen - H, Magnesium - Mg, Mercury - Hg

Step2: Recall atomic numbers and atomic masses

Element	Atomic Number ($Z$)	Approx. Atomic Mass ($A$, rounded)	Neutrons ($N=A - Z$)
Carbon	6	12	$12 - 6=6$
Fluorine	9	19	$19 - 9 = 10$
Europium	63	152	$152-63 = 89$
Bismuth	83	209	$209 - 83=126$
Hydrogen	1	1	$1 - 1 = 0$
Magnesium	12	24	$24 - 12 = 12$
Mercury	80	201	$201 - 80=121$

Step3: Write symbol - neutron number pairs

Barium: Ba, 81; Carbon: C, 6; Fluorine: F, 10; Europium: Eu, 89; Bismuth: Bi, 126; Hydrogen: H, 0; Magnesium: Mg, 12; Mercury: Hg, 121

Answer:

Barium: Ba, 81
Carbon: C, 6
Fluorine: F, 10
Europium: Eu, 89
Bismuth: Bi, 126
Hydrogen: H, 0
Magnesium: Mg, 12
Mercury: Hg, 121