Question

contents of this page will be cut out and pasted to your notebook.
pen numbers practice
helium
mg
zinc
br
aluminum
u
sodium
kr
calcium
ag

Explanation:

Step1: Recall the atomic number, mass number, proton, electron, and neutron relationships

• Atomic number \(Z\) = number of protons \(p\) = number of electrons \(e\) (for neutral atoms)
• Mass number \(A\) = number of protons \(p\) + number of neutrons \(n\)

Step2: Fill in the Helium row

• Symbol: \(He\)
• Number of protons: \(2\) (since atomic number \(Z = 2\))
• Number of electrons: \(2\) (neutral atom)
• Number of neutrons: \(A - Z=4 - 2 = 2\)

Step3: Fill in the Magnesium (\(Mg\)) row

• Element: Magnesium
• Number of protons: \(12\) (atomic number \(Z = 12\))
• Number of electrons: \(12\) (neutral atom)

Step4: Fill in the Zinc row

• Symbol: \(Zn\)
• Atomic number \(Z = 30\) (number of protons)
• Mass number \(A=30 + 35=65\)

Step5: Fill in the Bromine (\(Br\)) row

• Element: Bromine
• Atomic number \(Z = 35\) (number of protons)
• Mass number \(A = 80\)
• Number of neutrons: \(80 - 35=45\)

Step6: Fill in the Aluminum row

• Symbol: \(Al\)
• Number of protons: \(13\) (atomic number \(Z = 13\))
• Number of electrons: \(13\) (neutral atom)
• Number of neutrons: \(27 - 13 = 14\)

Step7: Fill in the Uranium (\(U\)) row

• Element: Uranium
• Atomic number \(Z = 92\) (number of protons)
• Mass number \(A=92 + 146=238\)

Step8: Fill in the Sodium row

• Symbol: \(Na\)
• Mass number \(A=11 + 12=23\)
• Number of protons: \(11\) (atomic number \(Z = 11\))
• Number of electrons: \(11\) (neutral atom)

Step9: Fill in the Krypton (\(Kr\)) row

• Element: Krypton
• Atomic number \(Z = 36\) (number of protons)
• Mass number \(A=36 + 48=84\)

Step10: Fill in the Calcium row

• Symbol: \(Ca\)
• Number of protons: \(20\) (atomic number \(Z = 20\))
• Number of electrons: \(20\) (neutral atom)
• Number of neutrons: \(40 - 20 = 20\)

Step11: Fill in the Silver (\(Ag\)) row

• Element: Silver
• Atomic number \(Z\): Let mass number \(A\), number of neutrons \(n = 61\). If we assume \(A\) (common silver isotope \(A = 108 + 1=109\) (but more accurately, for \(n = 61\), \(Z=A - n\). If we assume \(A = 108 + 1=109\) (but standard \(Ag\) has \(A = 108 + 1 = 109\) (more precisely, for \(n = 61\), \(Z=47\) (from periodic table), \(A=47+61 = 108\))
• Number of protons: \(47\)
• Number of electrons: \(47\)

Answer:

Element	Symbol	Atomic Number	Mass Number	# of Protons	# of Electrons	# of Neutrons
Magnesium	\(Mg\)	\(12\)	\(24\)	\(12\)	\(12\)	\(12\)
Zinc	\(Zn\)	\(30\)	\(65\)	\(30\)	\(30\)	\(35\)
Bromine	\(Br\)	\(35\)	\(80\)	\(35\)	\(35\)	\(45\)
Aluminum	\(Al\)	\(13\)	\(27\)	\(13\)	\(13\)	\(14\)
Uranium	\(U\)	\(92\)	\(238\)	\(92\)	\(92\)	\(146\)
Sodium	\(Na\)	\(11\)	\(23\)	\(11\)	\(11\)	\(12\)
Krypton	\(Kr\)	\(36\)	\(84\)	\(36\)	\(36\)	\(48\)
Calcium	\(Ca\)	\(20\)	\(40\)	\(20\)	\(20\)	\(20\)
Silver	\(Ag\)	\(47\)	\(108\)	\(47\)	\(47\)	\(61\)