Question

(b) Identify the term/substance underlined: 1) An element which has atoms with different mass number. II) An lon formed by gain of electrons. iii) A molecule which contains double covalent bond. iv) The element with the smallest atomic size in the 2" period. v) A solid non-metal with 5 electrons in M shell. (c) An element A has 6 electrons in the 'M' shell. State: 1 Its atomic number 2 Its valency 3 Its position in the periodic table 4 Is it a metal or a non-metal​

Answer 1

Answer:

It's your answer

Explanation:

(i) Atomic number: The atomic number is the total number of protons present in the atom. For example, the atomic number of sodium is 11. It contains 11 protons and 11 electrons.

(ii) Mass number: It is the sum of the number of neutrons and the number of protons. For example, the atomic number of magnesium is 12 which is equal to the number of protons, the number of neutrons of magnesium is 12. The mass number is equal to 24 (12+12).

(iii) Isotopes are the elements having same atomic number but different mass number. They have same chemical properties as the number of valence electrons are same. For example, 6C12, 6C13, 6C14

are the three isotopes of carbon. They have same atomic number but different mass number due to difference in the number of neutrons.

(iv) Isobars: They are elements having the same mass number but different atomic number.

For example, 18AR40, 19K40

are isobars having the same atomic mass but different atomic number.