Question

atomic structure worksheet
fill in the blanks for the elements in this chart. for the purposes of this chart, round all atomic masses to the nearest whole number.
element number of protons number of neutrons number of electrons atomic mass atomic number
lithium 3 4 3 7 3
carbon 6 12 6
chlorine 17 18 35 17
silver 108
82 207
calcium 20 20 20
tantalum 73 181
radium 88 138
samarium 150
uranium 146
148 95
lawrencium 159

Explanation:

Step1: Recall atomic - structure relationships

In a neutral atom, the number of protons = number of electrons. Atomic number = number of protons. Atomic mass ≈ number of protons+number of neutrons.

Step2: Fill in carbon's neutrons

For carbon, atomic mass = 12, number of protons = 6. Number of neutrons = atomic mass - number of protons = 12 - 6 = 6. Number of electrons = 6 (since it's neutral).

Step3: Fill in chlorine's electrons

For chlorine, number of protons = 17, so number of electrons = 17 (neutral atom).

Step4: Fill in silver's details

Atomic number of silver is 47. Number of protons = 47, number of electrons = 47. Number of neutrons = atomic mass - number of protons = 108 - 47 = 61.

Step5: Fill in the element with atomic mass 82 and atomic number 20

The element is calcium. Number of protons = 20, number of electrons = 20, number of neutrons = 82 - 20 = 62.

Step6: Fill in tantalum's neutrons and electrons

Number of electrons = 73 (neutral atom). Number of neutrons = atomic mass - number of protons = 181 - 73 = 108.

Step7: Fill in radium's electrons and atomic mass

Number of electrons = 88 (neutral atom). Atomic mass = number of protons+number of neutrons = 88 + 138 = 226.

Step8: Fill in samarium's protons, neutrons and electrons

Atomic number of samarium is 62. Number of protons = 62, number of electrons = 62, number of neutrons = 150 - 62 = 88.

Step9: Fill in uranium's protons and atomic mass

Atomic number of uranium is 92. Number of protons = 92, atomic mass = 92+146 = 238.

Step10: Fill in the element with 95 protons

The element is americium. Number of electrons = 95, number of neutrons = 148. Atomic mass = 95 + 148 = 243.

Step11: Fill in lawrencium's protons, electrons and atomic mass

Atomic number of lawrencium is 103. Number of protons = 103, number of electrons = 103, atomic mass = 103+159 = 262.

Answer:

Element	Number of Protons	Number of Neutrons	Number of Electrons	Atomic Mass	Atomic Number
carbon	6	6	6	12	6
chlorine	17	18	17	35	17
silver	47	61	47	108	47
calcium	20	62	20	82	20
tantalum	73	108	73	181	73
radium	88	138	88	226	88
samarium	62	88	62	150	62
uranium	92	146	92	238	92
americium	95	148	95	243	95
lawrencium	103	159	103	262	103