Atomic Radius Exploration
Explore the concept of atomic radius, its trends across the periodic table, and factors influencing its size for Grade 9 science students.
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Atomic Radius Exploration
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Read each question carefully and answer to the best of your ability. Show all your work for calculations.
1. What is the definition of atomic radius?
The distance from the nucleus to the outermost electron shell.
The total number of protons and neutrons in an atom.
The mass of an atom.
The number of electrons in the valence shell.
2. As you move across a period (from left to right) in the periodic table, what generally happens to the atomic radius?
It increases.
It decreases.
It remains constant.
It first increases then decreases.
3. As you move down a group in the periodic table, the atomic radius generally because of the addition of new shells.
4. The effective nuclear charge across a period, leading to a stronger attraction between the nucleus and the valence electrons, thus the atomic radius.
5. Shielding effect refers to the repulsion between valence electrons and inner-shell electrons, which reduces the effective nuclear charge felt by the valence electrons.
True
False
6. Cations are generally larger than their parent atoms because they have lost electrons.
True
False
7. Explain why atomic radius generally decreases across a period.
8. Describe the two main factors that influence atomic radius.
9. Draw a simple diagram illustrating the general trend of increasing atomic radius down a group and decreasing atomic radius across a period on a blank periodic table outline. Label the axes.