Isotopes

What are isotopes?

• Isotopes are atoms of the same element with different mass numbers.

• Isotopes are atoms of different elements with different mass numbers.

• Isotopes are atoms of different elements with same mass numbers.

• Isotopes are atoms of the same element with the same mass.

Which of the following statements holds true for the isotopes Chlorine-35 and Chlorine-37?

• They have similar physical properties.

• They have different chemical properties.

• They have similar chemical properties.

• They have different atomic numbers.

The composition of the nuclei of two atomic species X and Y is as follows:

X – 6 protons, 6 neutrons

Y – 6 protons, 8 neutrons

What is the mass number of both X and Y and what is the relation between X and Y.

• Mass number “X” = 12, Mass number “Y” = 12; atoms

• Mass number ”X” = 14, Mass number ”Y” = 12, isotopes

• Mass number ”X” = 12, Mass number ”Y” = 14, isotopes

• Mass number “X” = 14, Mass number “Y” = 14, isotopes

Identify the element represented in Question 3.

• Mg

• Na

• C

• N

Bromine occurs naturally in two stable isotopic forms - ₃₅⁷⁹Br, ₃₅ ⁸¹Br.

If the natural abundance of Bromine-79 and Bromine-81 is 49.7 per cent and 50.3 per cent, respectively, what is the average atomic mass of bromine?

• 80.5 u

• 80

• 80 u

• 79 u

Identify the number of neutrons present in ₃₅⁷⁹Br and ₃₅ ⁸¹Br.

• 45 and 46

• 44 and 46

• 46 and 44

• 46 and 45

What name is given to a pair of atoms such as ¹⁴ ₇N and ¹⁵₇N?

• Isobar

• Isotone

• Isotope

• Isochoric

¹⁴ ₇N and ¹⁵₇N have different ………………..

• Electronic configuration

• Atomic number

• Boiling points

• Chemical properties