Isotopes

Question 1

What are isotopes?

Answer 1

Atoms of the same element with the same number of protons but different number of neutrons.

They have the same chemical properties due to having the same electronic configuration.

Question 2

How do you calculate the relative atomic mass (RAM) using isotopes?

Answer 2

Use the formula: (M1 x P1) + (M2 x P2) … / 100.

Where M is mass and P is the percentage of each isotope.

Question 3

What is the RAM of chlorine given the percentages of Cl-35 (75%) and Cl-37 (25%)?

Answer 3

35.5

Calculation: (35 x 75) + (37 x 25) / 100.

Question 4

What is the method for calculating percentages of isotopes when the mass and RAM are given?

Answer 4

Find the ratio of differences between masses and RAM, then cross-multiply with total and 100 to get percentages.

Example: For Ca-39 and Ca-42 with RAM = 40.12, the ratios are used to find percentages.

Question 5

If the RAM of calcium is 40.12, what are the calculated percentages for Ca-39 and Ca-42?

Answer 5

Ca-39 = 37.3%, Ca-42 = 63.7%.

Calculated using the ratios 1.12 : 1.88 : 3.