Chemistry Topic: 1 - The Particulate nature of Matter

Question 1

The Particulate Nature of Matter

Describe particles in a solid, liquid, gas

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Answer 1

• In solids, particles only vibrate about fixed positions, regular structure.
• In liquids, particles can move around each other, collide ofen.
• In gases, particles more freely and at random in all directions, collide less often than in a liquid.

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Question 2

The Particulate Nature of Matter

Explain what happens to the temperature during melting and boiling.

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Answer 2

• During melting, the temperature stays constant as energy is used to weaken the intermoleular forces and change the substance from a solid to a liquid.
• During boiling, the temperature stays constant as energy is used to break the intermolecular forces and change the substance from a liquid to a gas.

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Question 3

The Particulate Nature of Matter

Describe an atom, a molecule and an ion.

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Answer 3

• An atom is the smallest part of an element.
• A group of atoms covalently bonded together (e.g O₂ or H₂O)
• An ion is a charged particle (e.g Na⁺ or SO₄²⁻)

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Question 4

The Particulate Nature of Matter

Describe diffusion. Explain the factors that affect diffusion.

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Answer 4

• Diffusion is the process by which different substances mix as a result of the random motions of their particles.
• The higher the temperature, the faster the rate of diffusion. The greater the molecular mass the slower the rate of diffusion.

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