BGCSE flashcards
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32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Quadratic formula
- For an equation ax² + bx + c = 0 with a ≠ 0, the solutions are x = (−b ± √(b² − 4ac)) / (2a).
- Pythagoras' theorem
- In a right-angled triangle, the square of the hypotenuse equals the sum of the squares of the other two sides: a² + b² = c².
- Probability addition rule
- For two events A and B, P(A or B) = P(A) + P(B) − P(A and B). If the events cannot occur together, the last term is zero.
- Mean, median, mode
- The mean is the sum of values divided by their number. The median is the middle value when data are ordered. The mode is the most frequent value.
- Compound interest formula
- A = P(1 + r/n)^(nt), where P is principal, r is annual interest rate as a decimal, n is compounds per year, and t is years.
- Polygon angle sum
- The interior angles of a polygon with n sides add to (n − 2) × 180°. The exterior angles of any convex polygon add to 360°.
- Active to passive
- Move the object to the subject position, use the correct form of 'be' plus the past participle, and add the original subject after 'by' if needed.
- Direct to indirect speech
- Reported speech usually shifts the tense back one step, changes pronouns to fit the reporter, and adjusts time words such as 'now' to 'then'.
- Its versus it's
- 'Its' is the possessive form of 'it', while 'it's' is a contraction of 'it is' or 'it has'. Replacing 'it's' with 'it is' tests correctness.
- Simile and metaphor
- A simile compares two things using 'like' or 'as'. A metaphor states that one thing is another without using 'like' or 'as'.
- Subject-verb agreement
- A singular subject takes a singular verb, and a plural subject takes a plural verb. With 'either ... or', the verb agrees with the nearer subject.
- Photosynthesis equation
- In the presence of light and chlorophyll, carbon dioxide and water react to form glucose and oxygen: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂.
- Ohm's law
- For a conductor at constant temperature, voltage equals current multiplied by resistance: V = IR, where V is volts, I is amperes, and R is ohms.
- Density formula
- Density is mass per unit volume: density = mass ÷ volume. It is measured in kilograms per cubic metre or grams per cubic centimetre.
- Ionic versus covalent bonding
- Ionic bonding transfers electrons from a metal to a non-metal, forming charged ions. Covalent bonding shares electron pairs between non-metal atoms.
- Mole formula
- The number of moles equals mass divided by molar mass: n = m ÷ M. One mole contains 6.02 × 10²³ particles.
- Osmosis
- Osmosis is the movement of water molecules from a dilute solution to a concentrated solution through a partially permeable membrane, down a water potential gradient.
- Bechuanaland Protectorate
- Britain declared Bechuanaland a protectorate in 1885. It became the independent Republic of Botswana on 30 September 1966, with Seretse Khama as first president.
- Map scale
- A map scale shows the relationship between map distance and ground distance. A scale of 1:50,000 means one centimetre on the map represents 50,000 centimetres on the ground.
- Contour lines
- Contour lines join points of equal height above sea level. Close lines indicate a steep slope, while widely spaced lines indicate a gentle slope.
- Primary and secondary sources
- Primary sources come from the period studied, such as letters or tools. Secondary sources interpret or analyse the past, such as textbooks and documentaries.
- Sustainable development
- Development that meets present needs without preventing future generations from meeting theirs. It balances economic growth, social welfare, and environmental protection.
- Setswana noun classes
- Setswana nouns are grouped by prefixes that control agreement. For people, mo- is singular and ba- is plural, as in motho and batho.
- Setswana greetings
- 'Dumela' means hello to one person and 'dumelang' to several. 'Le kae?' asks how are you; 'ke teng' replies that I am fine.
- Setswana question words
- Common Setswana question words include eng for what, mang for who, kae for where, leng for when, and jang for how.
- Setswana numbers one to five
- The Setswana numbers one to five are nngwe, pedi, tharo, nne, and tlhano. These are used when counting objects in everyday speech.
- Setswana proverb example
- 'Motho ke motho ka batho' means a person is a person through other people. It emphasises community, cooperation, and shared humanity.
- Lab safety goggles
- Safety goggles protect eyes from splashes, fumes, and flying particles during experiments. They must be worn whenever chemicals, heat, or glassware are used.
- RICE first aid
- For a sprain, use rest, ice, compression, and elevation. Ice reduces swelling, compression supports the joint, and elevation limits fluid buildup.
- Vernier caliper reading
- Read the main scale before the zero mark of the vernier scale, then add the vernier division that aligns with a main-scale mark, multiplied by the least count.
- Food danger zone
- Bacteria multiply fastest between 5°C and 60°C, called the danger zone. Keep hot food above 60°C and cold food below 5°C.
- Orthographic projection
- Orthographic projection shows a three-dimensional object as separate front, top, and side views. First-angle projection places the top view below the front view.