Atoms and the periodic table

Name the three main subatomic particles and state their charges.

What does the atomic number tell you about an atom?

What does the mass number tell you about an atom?

How do you calculate the number of neutrons in an atom?

What is an electron shell?

Why are valence electrons important in chemical reactions?

What is a group in the periodic table?

What is a period in the periodic table?

Why do elements in the same group often have similar properties?

Give one example of a periodic trend or pattern.

For an atom with atomic number 12 and mass number 24, identify the number of protons, electrons and neutrons. Explain each step.

Draw or describe the electron arrangement of sodium, atomic number 11. Explain how this arrangement helps predict sodium’s reactivity.

Compare lithium and sodium using their position in the periodic table, electron arrangements and likely chemical behaviour.

Explain why noble gases are generally unreactive using valence electrons and full outer shells.

Magnesium forms Mg²⁺ ions. Explain how this links to its electron arrangement and position in Group 2.

Chlorine forms Cl⁻ ions. Explain how this links to its valence electrons and position in Group 17.

Use atomic structure to explain the difference between an atom and an ion. Include one positive and one negative ion example.

Explain how Mendeleev’s periodic table used patterns to organise elements and predict properties of undiscovered elements.

Evaluate this claim: “The periodic table is just a list of elements.” Explain why the table is more useful than a simple list.

Write a full scientific explanation of how electron structure relates to the chemical properties of elements, using at least two element examples.