Question

protons, neutrons, and electrons practice worksheet
calculating the number of each particle in an atom:

protons = atomic number

electrons = protons

neutrons = atomic mass - atomic number or big # - small #

use the periodic table to find the numbers of protons, neutrons, and electrons for atoms of the following
elements.
boron
sodium
y
copper
tc
pb
thallium
h
carbon
n
ba
calcium
si
argon
mg

Explanation:

Step1: Sodium

• Protons: \( \text{Protons}=\text{Atomic Number} = 11\)
• Electrons: \( \text{Electrons}=\text{Protons}=11\)
• Neutrons: \( \text{Neutrons}=\text{Mass Number}-\text{Atomic Number}=24 - 11=13\)

Step2: Yttrium (Y)

• Protons: \( \text{Protons}=\text{Electrons}=39\)
• Atomic Number: \( \text{Atomic Number}=39\)
• Neutrons: \( \text{Neutrons}=\text{Mass Number}-\text{Atomic Number}=89 - 39 = 50\)

Step3: Copper

• Atomic Number: \( \text{Atomic Number}=29\)
• Protons: \( \text{Protons}=29\)
• Electrons: \( \text{Electrons}=29\)
• Mass Number: \( \text{Mass Number}=\text{Protons}+\text{Neutrons}=29 + 35=64\)

Step4: Technetium (Tc)

• Protons: \( \text{Protons}=43\)
• Electrons: \( \text{Electrons}=43\)
• Atomic Number: \( \text{Atomic Number}=43\)
• Neutrons: \( \text{Neutrons}=\text{Mass Number}-\text{Atomic Number}=98 - 43=55\)

Step5: Lead (Pb)

• Atomic Number: \( \text{Atomic Number}=82\) (from periodic table)
• Protons: \( \text{Protons}=82\)
• Electrons: \( \text{Electrons}=82\)
• Neutrons: \( \text{Neutrons}=\text{Mass Number}-\text{Atomic Number}=207 - 82=125\)

Step6: Thallium

• Protons: \( \text{Protons}=81\)
• Electrons: \( \text{Electrons}=81\)
• Neutrons: \( \text{Neutrons}=\text{Mass Number}-\text{Atomic Number}=204 - 81=123\)

Step7: Hydrogen (H)

• Atomic Number: \( \text{Atomic Number}=1\)
• Protons: \( \text{Protons}=1\)
• Electrons: \( \text{Electrons}=1\)
• Mass Number: \( \text{Mass Number}=\text{Protons}+\text{Neutrons}=1+0 = 1\)

Step8: Carbon

• Atomic Number: \( \text{Atomic Number}=6\)
• Protons: \( \text{Protons}=6\)
• Electrons: \( \text{Electrons}=6\)
• Neutrons: \( \text{Neutrons}=\text{Mass Number}-\text{Atomic Number}=12 - 6=6\)

Step9: Nitrogen (N)

• Atomic Number: \( \text{Atomic Number}=7\)
• Protons: \( \text{Protons}=7\)
• Electrons: \( \text{Electrons}=7\)
• Mass Number: \( \text{Mass Number}=\text{Protons}+\text{Neutrons}=7 + 7=14\)

Step10: Barium (Ba)

• Protons: \( \text{Protons}=\text{Electrons}=56\)
• Atomic Number: \( \text{Atomic Number}=56\)
• Neutrons: \( \text{Neutrons}=\text{Mass Number}-\text{Atomic Number}\) (Mass Number not given, assume standard \( \text{Mass Number}=137\), \( \text{Neutrons}=137 - 56 = 81\))

Step11: Calcium

• Atomic Number: \( \text{Atomic Number}=20\)
• Protons: \( \text{Protons}=20\)
• Electrons: \( \text{Electrons}=20\)
• Mass Number: \( \text{Mass Number}=\text{Protons}+\text{Neutrons}\) (Assume standard \( \text{Mass Number}=40\), \( \text{Neutrons}=40 - 20=20\))

Step12: Silicon (Si)

• Protons: \( \text{Protons}=\text{Electrons}=14\)
• Atomic Number: \( \text{Atomic Number}=14\)
• Neutrons: \( \text{Neutrons}=\text{Mass Number}-\text{Atomic Number}\) (Assume standard \( \text{Mass Number}=28\), \( \text{Neutrons}=28 - 14=14\))

Step13: Argon

• Protons: \( \text{Protons}=18\)
• Electrons: \( \text{Electrons}=18\)
• Mass Number: \( \text{Mass Number}=\text{Protons}+\text{Neutrons}\) (Assume standard \( \text{Mass Number}=40\), \( \text{Neutrons}=40 - 18=22\))

Step14: Magnesium (Mg)

• Atomic Number: \( \text{Atomic Number}=12\)
• Mass Number: \( \text{Mass Number}=\text{Protons}+\text{Neutrons}=12 + 12=24\)

Answer:

Name of Element	Element Symbol	Mass Number	Atomic Number	Protons	Neutrons	Electrons
Sodium	Na	24	11	11	13	11
Yttrium	Y	89	39	39	50	39
Copper	Cu	64	29	29	35	29
Technetium	Tc	98	43	43	55	43
Lead	Pb	207	82	82	125	82
Thallium	Tl	204	81	81	123	81
Hydrogen	H	1	1	1	0	1
Carbon	C	12	6	6	6	6
Nitrogen	N	14	7	7	7	7
Barium	Ba	137	56	56	81	56
Calcium	Ca	40	20	20	20	20
Silicon	Si	28	14	14	14	14
Argon	Ar	40	18	18	22	18
Magnesium	Mg	24	12	12	12	12