Question

(a) Atomic number of 'X'
(b) Atomic mass of 'X'
(c) Valence electrons
(d) Valency of 'X'
(e) 'X' should be metal or non-metal.​

Answer 1

Explanation:

1. The atomic number of an element 'X' is 16 . In the modern periodic table the element 'X' belongs to this block and period.
2. A property closely related to an atom's mass number is its atomic mass. The atomic mass of a single atom is simply its total mass and is typically expressed in atomic mass units or amu. By definition, an atom of carbon with six neutrons, carbon-12, has an atomic mass of 12 amu.
3. In chemistry and physics, a valence electron is an outer shell electron that is associated with an atom, and that can participate in the formation of a chemical bond if the outer shell is not closed; in a single covalent bond, both atoms in the bond contribute one valence electron in order to form a shared pair.
4. Solution. (a) The number of valence electrons in element X is 2 because this element belongs to group
5. Atomic number = Number of protons = 8 (b) Atomic mass = Number of protons + Number of neutrons = 8 + 10 = 18 u (c) Valence electrons = 6 (d) Valency of 'X' =8-6=2 (e) 'X' should be non-metal because there are six valence electrons hence it will take two more electrons to complete its outer most shell.

Answer 2

Answer:

(a) 16

The atomic number of an element 'X' is 16.

(c) In chemistry and physics, a valence electron is an outer shell electron that is associated with an atom, and that can participate in the formation of a chemical bond if the outer shell is not closed; in a single covalent bond, both atoms in the bond contribute one valence electron in order to form a shared pair.

(d) 2

Solution. (a) The number of valence electrons in element X is 2 because this element belongs to group 2.

(e) Atomic number = Number of protons = 8 (b) Atomic mass = Number of protons + Number of neutrons = 8 + 10 = 18 u (c) Valence electrons = 6 (d) Valency of 'X' =8-6=2 (e) 'X' should be non-metal because there are six valence electrons hence it will take two more electrons to complete its outer most shell..

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