Name or state the following :
(a) An element having valency zero.
(b) Metal with valency one.
(c) Atoms of the same element differing in mass numbers.
(d) Elements having same mass number but different atomic number.
(e) Bond formed by transfer of electron(s).
(f) Ion formed by gain of electron(s).
Name or state the following :
(a) An element having valency zero.
(b) Metal with valency one.
(c) Atoms of the same element differing in mass numbers.
(d) Elements having same mass number but different atomic number.
(e) Bond formed by transfer of electron(s).
(f) Ion formed by gain of electron(s).
a)They are called Noble or Inert gases. It starts from He. The helium atom has only the 1s orbital in its only shell, and it is completely filled with 2 electrons. Its electronic configuration is 1s2. Therefore, helium and the other inert gases with complete octets normally do not take part in chemical reactions. They are considered as zero-valent elements.
b)
- Sodium. Na. Valency: 1.
- Silver. Ag. Valency: 1.
- Potassium. K. Valency: 1.
- Lithium. Li. Valency: 1.
c)The atoms of a chemical element can exist in different types. These are called isotopes. They have the same number of protons (and electrons), but different numbers of neutrons. Different isotopes of the same element have different masses
d)They have same mass number but different atomic number. Isotopes are of same element and have same chemical properties but different physical properties. Isobars are different elements who have same Mass number. They have different number of protons and neutrons but sum of protons and neutrons is same
e)An ionic bond is a type of chemical bond formedthrough an electrostatic attraction between two oppositely charged ions. Ionic bonds are formedbetween a cation, which is usually a metal, and an anion, which is usually a nonmetal.
A covalent bondinvolves a pair of electrons being shared between atoms.
f)Ions are electrically charged particles formed when atoms lose or gain electrons. They have the same electronic structures as noble gases. Metal atoms formpositive ions, while non-metal atoms form negative ions. The strong electrostatic forces of attraction between oppositely charged ions are called ionic bonds.
a)They are called Noble or Inert gases. It starts from He. The helium atom has only the 1s orbital in its only shell, and it is completely filled with 2 electrons. Its electronic configuration is 1s2. Therefore, helium and the other inert gases with complete octets normally do not take part in chemical reactions. They are considered as zero-valent elements.
b)
- Sodium. Na. Valency: 1.
- Silver. Ag. Valency: 1.
- Potassium. K. Valency: 1.
- Lithium. Li. Valency: 1.
c)The atoms of a chemical element can exist in different types. These are called isotopes. They have the same number of protons (and electrons), but different numbers of neutrons. Different isotopes of the same element have different masses
d)They have same mass number but different atomic number. Isotopes are of same element and have same chemical properties but different physical properties. Isobars are different elements who have same Mass number. They have different number of protons and neutrons but sum of protons and neutrons is same
e)An ionic bond is a type of chemical bond formedthrough an electrostatic attraction between two oppositely charged ions. Ionic bonds are formedbetween a cation, which is usually a metal, and an anion, which is usually a nonmetal.
A covalent bondinvolves a pair of electrons being shared between atoms.
f)Ions are electrically charged particles formed when atoms lose or gain electrons. They have the same electronic structures as noble gases. Metal atoms formpositive ions, while non-metal atoms form negative ions. The strong electrostatic forces of attraction between oppositely charged ions are called ionic bonds.
