Form 1 • Chemistry
Welcome! In this lesson you’ll explore what science is, define chemistry, review its main branches, and see how it powers everyday life in Malawi and beyond. You’ll also learn key safety rules, common apparatus, how to measure physical quantities, and the meaning of hazard symbols.
Lesson goals: Define science & chemistry; name 6 branches; apply lab safety.
Time: 50–60 minutes
Assessment: Exit ticket + quick quiz
Science is the systematic study of nature, the changes involved, and the reasons for those changes.
Chemistry is the study of the structure, composition, and behavior of substances under various conditions.
Separation, identification, and quantification of chemical compositions.
Applying physical & chemical processes to convert raw materials into products.
Study of carbon, its compounds, oxides, and carbonates.
Materials of non‑biological origin.
How compounds and their constituents interact and react.
Chemical processes in the environment, especially due to human activity.
Chemical processes purify water to make it safe for consumption.
Preparing nsima or brewing tea involves chemical reactions.
Development and manufacturing of medicines.
Refining sugar with lime; baking powder to make bread rise.
Creating effective cleaning products.
Developing agricultural chemicals.
Distillation breaks crude oil into components.
Chemistry drives new ideas and technologies.
Laboratory: A space where scientific experiments, particularly in chemistry, are conducted.
Safety rules keep the lab safe for people, chemicals, and apparatus.
Sizes include 25 ml, 50 ml, 100 ml, 500 ml, and 1000 ml.
A sealed glass tube with mercury or alcohol that expands when heated.
Reading time: minutes:seconds:hundredths. Example: 11:14:01 = 11 min, 14 s, 01 hundredth.
Symbols on containers warn users about potential dangers.
Can detonate unexpectedly. Handle with extreme care and follow instructions.
Poisonous; can cause death. If it contacts skin, wash thoroughly with water.
Can intensify fire or cause substances to combust in presence of oxidizers.
Harmful to skin or health. Avoid contact and inhalation; risky for asthma sufferers.
SI (Système International d'Unités) are internationally accepted units used by scientists. Quantities are meaningless without appropriate units.
Cannot be defined in terms of other quantities; units are not combinations of other units.
Defined from basic quantities; units combine two or more base units.
A scientific investigation is a systematic process used by scientists to find solutions to problems or answers to questions. It can lead to new discoveries or confirm existing knowledge. In earlier times, investigations were less systematic due to a lack of advanced equipment.
Note: Scientific investigation is an ongoing process. Even established theories may be modified if new evidence emerges.
UNIT 2
Standard form (scientific notation) is a method for writing very large or small numbers. It consists of:
Move the decimal point from left to right; the power of 10 will be positive.
Move the decimal point from right to left; the power of 10 will be negative.
Significant figures are digits that reflect the precision of a number.
The result of operations should reflect the least number of significant figures from the inputs.
Accuracy: How close a measurement is to the actual value.
Precision: How close multiple measurements are to each other.
Example: 30.01g, 30.02g, 30.03g → both accurate (close to 30.0g) and precise (close to each other).
Graphs visually represent experimental data.
Line Graphs: Good for trends, but can be cluttered.
Bar Graphs: Good for comparisons, not for continuous data.
Pie Charts: Good for percentages, but poor for large datasets.
Matter is defined as anything that has mass and occupies space.
Matter is made up of small particles called molecules, which are composed of atoms, the smallest units of matter.
Atom: The smallest particle of matter.
Movement of particles from higher to lower concentration. Fastest in gases, slow or nonexistent in solids.
Investigating Diffusion in Liquids: Use beaker, water, potassium permanganate crystals, and thistle funnel. Pour water without shaking; observe purple spread.
Examples: Smelling food, dissolving sugar, coffee grains spreading, scent from clothes.
Substances that cannot be broken down chemically. Composed of only one type of atom.
Types: Single atoms (noble gases), Molecular form (O₂ for oxygen).
Discovered Elements: 115 total; 99 naturally occurring, 24 artificially created.
Hydrogen, Helium, Lithium, Beryllium, Boron, Carbon, Nitrogen, Oxygen, Fluorine, Neon, Sodium, Magnesium, Aluminum, Silicon, Phosphorus, Sulfur, Chlorine, Argon, Potassium, Calcium.
Shorthand for elements. One or two letters, first capitalized. Example: Hydrogen (H), Helium (He), Sodium (Na).
Latin-Based Symbols: Sodium - Natrium (Na), Potassium - Kalium (K), Copper - Cuprum (Cu), Iron - Ferrum (Fe), Silver - Argentum (Ag), Lead - Plumbum (Pb), Gold - Aurum (Au), Mercury - Hydrargyrum (Hg).