Question

atomic structure worksheet
period 4
list the 3 subatomic particles, their charges, masses and where in the atom they are located in the chart below:
subatomic particle electrical charge location in atom relative mass (amu)
protons
electrons
neutrons
describe how to determine the number of each subatomic particle in an atom below
proton: equal to atomic #
electron: equal to atomic #
neutron: mass - atomic #
fill in the chart for the elements below. round all atomic masses to the nearest whole number:
element symbol atomic number atomic mass # of protons # of electrons # of neutrons
sodium na 11 22.990 11 11 12
copper cu 29 63.546 29 29 35
chlorine cl 17 35.45 17 17 18
silver ag 47 107.87 47 47 61
lead pb 82 207.2 82 82 125
calcium ca 20 40.078 20 20 20
hafnium hf 72 178.49 72 72 107
radon rn 86 222 86 86 136
neptunium np 93 93 237 52
uranium u 92 238.03 92 92
potassium

Explanation:

Step1: Recall sub - atomic particle properties

Protons have a positive charge (+1), are located in the nucleus, and have a relative mass of approximately 1 amu. Electrons have a negative charge (- 1), orbit the nucleus, and have a very small relative mass (negligible compared to protons and neutrons, often considered as 0 amu). Neutrons have no charge (neutral), are located in the nucleus, and have a relative mass of approximately 1 amu.

Step2: Determine number of sub - atomic particles

The number of protons in an atom is equal to its atomic number. In a neutral atom, the number of electrons is equal to the number of protons (equal to the atomic number). The number of neutrons is calculated as the atomic mass (rounded to the nearest whole number) minus the atomic number.

Step3: Fill in the element chart

For sodium (Na), atomic number = 11, atomic mass ≈ 23. Number of protons = 11, number of electrons = 11, number of neutrons = 23 - 11=12.
For copper (Cu), atomic number = 29, atomic mass ≈ 64. Number of protons = 29, number of electrons = 29, number of neutrons = 64 - 29 = 35.
For chlorine (Cl), atomic number = 17, atomic mass ≈ 35. Number of protons = 17, number of electrons = 17, number of neutrons = 35 - 17 = 18.
For silver (Ag), atomic number = 47, atomic mass ≈ 108. Number of protons = 47, number of electrons = 47, number of neutrons = 108 - 47 = 61.
For lead (Pb), atomic number = 82, atomic mass ≈ 207. Number of protons = 82, number of electrons = 82, number of neutrons = 207 - 82 = 125.
For calcium (Ca), atomic number = 20, atomic mass ≈ 40. Number of protons = 20, number of electrons = 20, number of neutrons = 40 - 20 = 20.
For hafnium (Hf), atomic number = 72, atomic mass ≈ 178. Number of protons = 72, number of electrons = 72, number of neutrons = 178 - 72 = 106.
For radon (Rn), atomic number = 86, atomic mass ≈ 222. Number of protons = 86, number of electrons = 86, number of neutrons = 222 - 86 = 136.
For neptunium (Np), atomic number = 93, atomic mass ≈ 237. Number of protons = 93, number of electrons = 93, number of neutrons = 237 - 93 = 144.
For uranium (U), atomic number = 92, atomic mass ≈ 238. Number of protons = 92, number of electrons = 92, number of neutrons = 238 - 92 = 146.
For potassium (K), atomic number = 19, atomic mass ≈ 39. Number of protons = 19, number of electrons = 19, number of neutrons = 39 - 19 = 20.

Answer:

Element	Symbol	Atomic Number	Atomic Mass (rounded)	# of Protons	# of Electrons	# of Neutrons
copper	Cu	29	64	29	29	35
chlorine	Cl	17	35	17	17	18
silver	Ag	47	108	47	47	61
lead	Pb	82	207	82	82	125
calcium	Ca	20	40	20	20	20
hafnium	Hf	72	178	72	72	106
radon	Rn	86	222	86	86	136
neptunium	Np	93	237	93	93	144
uranium	U	92	238	92	92	146
potassium	K	19	39	19	19	20