Question

q.7. write the z, a, number of subatomic particles in the following:

	ca	ca²⁺	s	s²⁻
a
#protons
# neutrons
# electrons

q.8. what are the atomic number, mass number, number of protons and neutrons in the isotope of fe - 58.
ans.
z =
a=
p⁺=
n⁰=
e⁻=

Explanation:

Step1: Recall atomic number (Z) and mass number (A) concepts

Atomic number (Z) is the number of protons. Mass number (A) is the sum of protons and neutrons. For neutral atoms, number of electrons = number of protons. For ions, adjust electrons based on charge.

Step2: For Ca

Calcium (Ca) has atomic number Z = 20. Its most common isotope has mass number A = 40. Number of protons = Z = 20. Number of neutrons = A - Z = 40 - 20 = 20. For neutral Ca, number of electrons = 20.

Step3: For Ca²⁺

Z remains 20 (number of protons doesn't change with ion - formation). A remains 40. Number of protons = 20. Number of neutrons = 20. Since it has a + 2 charge, number of electrons = 20 - 2=18.

Step4: For S

Sulfur (S) has atomic number Z = 16. Its most common isotope has mass number A = 32. Number of protons = Z = 16. Number of neutrons = A - Z = 32 - 16 = 16. For neutral S, number of electrons = 16.

Step5: For S²⁻

Z remains 16. A remains 32. Number of protons = 16. Number of neutrons = 16. Since it has a - 2 charge, number of electrons = 16+2 = 18.

Step6: For Fe - 58

For the isotope Fe - 58, atomic number Z of iron is 26. Mass number A = 58. Number of protons p⁺=Z = 26. Number of neutrons n⁰=A - Z = 58 - 26 = 32. For a neutral Fe atom, number of electrons e⁻=Z = 26.

	Ca	Ca²⁺	S	S²⁻
A	40	40	32	32
#Protons	20	20	16	16
# Neutrons	20	20	16	16
# Electrons	20	18	16	18

For Fe - 58:
Z = 26
A = 58
p⁺ = 26
n⁰ = 32
e⁻ = 26

Answer:

	Ca	Ca²⁺	S	S²⁻
A	40	40	32	32
#Protons	20	20	16	16
# Neutrons	20	20	16	16
# Electrons	20	18	16	18

Z = 26
A = 58
p⁺ = 26
n⁰ = 32
e⁻ = 26