Question

1. give three examples of isotopes and their uses, not discussed in class. 12. what are the three isotopes of neon? how many protons, neutrons and electrons does each isotope have? which are the same, which are different? 13. three chromium isotopes are chromium - 50, chromium - 52, and chromium - 53. how many neutrons are in each isotope, given that chromium has an atomic number of 24? 14. what is the mass number represented by in the isotope notation ⁷⁹₁₉₇au? a) 79 b) 197 c) au d) gold

Explanation:

11.

Step1: Define isotopes

Isotopes are atoms of the same element with different numbers of neutrons.

Step2: Provide examples

• Carbon - 12: Used in radiocarbon dating. It has 6 protons, 6 neutrons and 6 electrons.
• Carbon - 14: Also used in radiocarbon dating. It has 6 protons, 8 neutrons and 6 electrons.
• Uranium - 235: Used as a fuel in nuclear reactors and in nuclear weapons. It has 92 protons, 143 neutrons and 92 electrons.

Step1: Identify neon isotopes

The three isotopes of neon are neon - 20, neon - 21 and neon - 22.

Step2: Determine sub - atomic particle numbers

• Neon - 20: Atomic number of neon is 10. So, it has 10 protons, 10 electrons. Mass number is 20, so number of neutrons = 20 - 10=10.
• Neon - 21: Has 10 protons, 10 electrons. Mass number is 21, so number of neutrons = 21 - 10 = 11.
• Neon - 22: Has 10 protons, 10 electrons. Mass number is 22, so number of neutrons = 22 - 10 = 12.

Step3: Compare isotopes

Protons are the same (10) for all isotopes as they are of the same element. Electrons are the same (10) in neutral atoms. Neutrons are different (10, 11 and 12 for neon - 20, neon - 21 and neon - 22 respectively).

Step1: Recall mass - number formula

Mass number (A)=Number of protons (Z)+Number of neutrons (N). The atomic number of chromium (Z) = 24.

Step2: Calculate neutrons for each isotope

• Chromium - 50: N = A - Z=50 - 24 = 26 neutrons.
• Chromium - 52: N = A - Z=52 - 24 = 28 neutrons.
• Chromium - 53: N = A - Z=53 - 24 = 29 neutrons.

Answer:

Carbon - 12 (used in radiocarbon dating, 6 protons, 6 neutrons, 6 electrons), Carbon - 14 (used in radiocarbon dating, 6 protons, 8 neutrons, 6 electrons), Uranium - 235 (used as nuclear fuel and in nuclear weapons, 92 protons, 143 neutrons, 92 electrons)

12.