Question

atomic # =
atomic mass =

of protons =

of neutrons =

of electrons =

atomic # =
atomic mass =

of protons =

of neutrons =

of electrons =

Explanation:

Step1: Recall the definitions

• Atomic number (\(Z\)): The number of protons in an atom. It is given at the top of the element box in the periodic table.
• Atomic mass (\(A\)): Given at the bottom of the element box.
• Number of protons (\(p\)): Equal to the atomic number.
• Number of neutrons (\(n\)): \(n=A - Z\) (approximate, as atomic mass is average).
• Number of electrons (\(e\)): In a neutral atom, \(e = p\) (equal to atomic number).

Step2: For Lithium (\(Li\))

• Atomic number (\(Z\)): \(3\) (from top of the box).
• Atomic mass (\(A\)): \(6.941\) (from bottom of the box).
• Number of protons (\(p\)): \(3\) (since \(p = Z\)).
• Number of neutrons (\(n\)): \(n=6.941 - 3\approx4\) (approximate, as atomic mass is average).
• Number of electrons (\(e\)): \(3\) (since \(e=p\) for neutral atom).

Step3: For Bromine (\(Br\))

• Atomic number (\(Z\)): \(35\) (from top of the box).
• Atomic mass (\(A\)): \(79.904\) (from bottom of the box).
• Number of protons (\(p\)): \(35\) (since \(p = Z\)).
• Number of neutrons (\(n\)): \(n=79.904 - 35\approx45\) (approximate, as atomic mass is average).
• Number of electrons (\(e\)): \(35\) (since \(e=p\) for neutral atom).

Answer:

• For Lithium:
• Atomic # = \(3\)
• Atomic Mass = \(6.941\)
• # of Protons = \(3\)
• # of Neutrons ≈ \(4\)
• # of Electrons = \(3\)
• For Bromine:
• Atomic # = \(35\)
• Atomic Mass = \(79.904\)
• # of Protons = \(35\)
• # of Neutrons ≈ \(45\)
• # of Electrons = \(35\)