Table of contents

1. The Chemical World9m
- The Scientific Method
  9m
2. Measurement and Problem Solving2h 19m
3. Matter and Energy2h 15m
4. Atoms and Elements2h 33m
5. Molecules and Compounds1h 50m
6. Chemical Composition1h 23m
7. Chemical Reactions1h 43m
8. Quantities in Chemical Reactions1h 8m
9. Electrons in Atoms and the Periodic Table2h 32m
10. Chemical Bonding2h 10m
11 Gases2h 7m
12. Liquids, Solids, and Intermolecular Forces1h 11m
13. Solutions3h 1m
14. Acids and Bases2h 14m
15. Chemical Equilibrium1h 27m
16. Oxidation and Reduction1h 33m
17. Radioactivity and Nuclear Chemistry53m

4. Atoms and Elements

Ions (Simplified)

Introduction to Chemistry

4. Atoms and Elements

Ions (Simplified)

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Multiple Choice

One isotope of a metallic element has a mass number of 65 and 35 neutrons in the nucleus. The cation that this atom forms has 28 electrons. What is the symbol of the cation?

⁶⁵Zn

⁶⁵Ga³⁺

⁶⁵Zn²⁺

⁶⁵Ni²⁺

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Verified step by step guidance

Identify the number of protons in the isotope. The mass number is the sum of protons and neutrons. Given the mass number is 65 and there are 35 neutrons, calculate the number of protons: 65 - 35 = 30 protons.

Determine the element using the number of protons. The atomic number, which is the number of protons, identifies the element. An atomic number of 30 corresponds to the element Zinc (Zn).

Consider the cation formation. The problem states the cation has 28 electrons. Since the neutral atom of Zinc has 30 electrons (equal to the number of protons), losing 2 electrons results in 28 electrons.

Determine the charge of the cation. Losing 2 electrons gives the cation a 2+ charge because there are 2 more protons than electrons.

Combine the information to write the symbol of the cation. The element is Zinc (Zn) with a mass number of 65 and a 2+ charge, so the symbol is 65Zn2+.