Chemistry Concepts: Atomic Theory & Changes of State

What is the reason tap water cannot be used for chemical analysis?

Describe the process of fractional distillation in relation to crude oil.

How did Dalton characterize atoms, and what was his atomic model known as?

Why are noble gases considered inert?

What classification did Mendeleeve use for organizing elements in the periodic table, and what group did he overlook?

What fundamental theory did John Dalton present regarding atoms?

How do groups in the periodic table affect the electrons in an atom?

What does a higher melting or boiling point indicate about a substance's particles?

What are the four key steps involved in the process of water purification?

Describe the process of dissolving in terms of solute and solvent.

What is the process of purifying seawater called?

Explain the significance of the RF (retention factor) in chromatography.

What are the two changes of state that occur in simple distillation?

Atomic Theory

John Dalton proposed the first atomic theory, picturing atoms as tiny, hard spheres.
Modern atomic models show atoms with roughly spherical electron shells.
Atomic mass is the sum of protons and neutrons in the nucleus.
Atomic number is the number of protons.
Elements in the same group have the same number of electrons in their outer shell.
Elements in the same period have increasing numbers of electron shells

Changes of State

Cooling curves illustrate changes of state (e.g., melting, freezing) in relation to temperature.
Changes of state involve physical changes (e.g., melting, freezing).
Chemical changes can't be reversed easily.
Volatiles are liquids with weak intermolecular forces that change state easily, while viscous liquids have strong intermolecular forces and are thick.

Chemical Changes & Dissolving

Dissolving involves solvent molecules bombarding solute particles, breaking intermolecular forces.
Chromatography separates substances based on different traveling speeds.
Simple distillation separates liquids with different boiling points.

Water Purification

Potable water is safe to drink.
Water sources include reservoirs and aquifers.
Water purification methods include screening, sedimentation, filtration, and sterilization (e.g., UV exposure).

Fractional Distillation

Crude oil is separated into useful fractions through fractional distillation.
Fractions include petroleum gas, petrol, kerosene, diesel, industrial fuel, lubricating oil, etc.
Each fraction has a different boiling point, allowing for separation.

The Periodic Table

Elements on the periodic table are organized by increasing atomic numbers.
Different Groups on the Periodic Table have similar properties.
Elements' properties determine how they are grouped.
Some elements are reactive (often metals) while some are inert (noble gasses).

This quiz covers essential chemistry concepts, including atomic theory, changes of state, and the nature of chemical changes. Understand the key components of atomic structure, the processes of melting and freezing, and the differences between physical and chemical changes. Test your knowledge and reinforce your understanding of these foundational topics in chemistry.