RBSE VU General Science flashcards
RBSE VU General Science · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Sublimation
- The direct change of a solid into a gas without passing through the liquid state, e.g., dry ice (solid carbon dioxide) or iodine when heated.
- Homogeneous mixture
- A mixture with uniform composition throughout, where components are not visibly separate, such as salt solution or air; also called a solution.
- Chromatography
- A separation technique in which components of a mixture move at different rates through a stationary phase carried by a mobile phase, used to separate coloured pigments or dissolved substances.
- Atomic number
- The number of protons in the nucleus of an atom, which defines the element and determines its position in the periodic table.
- Isotopes
- Atoms of the same element with the same number of protons but different numbers of neutrons, giving different mass numbers; they have identical chemical properties.
- Ionic bond
- The electrostatic attraction between oppositely charged ions formed when a metal atom loses electrons and a non-metal atom gains them, as in sodium chloride.
- Exothermic reaction
- A chemical reaction that releases energy to the surroundings, usually as heat, causing a temperature rise; combustion and neutralisation are examples.
- Displacement reaction
- A reaction in which a more reactive element displaces a less reactive element from its compound, such as zinc displacing copper from copper sulfate solution.
- Catalyst
- A substance that increases the rate of a chemical reaction by providing an alternative pathway with lower activation energy, without being used up itself.
- pH scale
- A scale from 0 to 14 measuring hydrogen ion concentration: below 7 is acidic, 7 is neutral, and above 7 is alkaline; each unit is a tenfold change.
- Neutralisation
- The reaction between an acid and a base to form a salt and water, for example hydrochloric acid reacting with sodium hydroxide to give sodium chloride and water.
- Weak acid
- An acid that only partially ionises in water, producing fewer hydrogen ions than a strong acid of the same concentration, such as ethanoic acid.
- Reactivity series
- A list of metals ordered by their chemical reactivity, from potassium (most reactive) to gold (least reactive), used to predict displacement reactions and extraction methods.
- Alloy
- A mixture of a metal with other elements, often making it harder and stronger than the pure metal, such as steel (iron and carbon) or brass (copper and zinc).
- Alkane
- A saturated hydrocarbon containing only single carbon–carbon bonds, with the general formula CₙH₂ₙ₊₂, such as methane (CH₄) and propane (C₃H₈).
- Mitochondrion
- A membrane-bound organelle in eukaryotic cells where aerobic respiration takes place, releasing energy as ATP from glucose and oxygen.
- Photosynthesis
- The process in chloroplasts where green plants use light energy to convert carbon dioxide and water into glucose and oxygen, summarised as 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂.
- Xylem
- Plant tissue made of hollow dead cells that transports water and dissolved minerals upward from the roots to the leaves, also providing support.
- Meiosis
- A type of cell division that produces four genetically different haploid gametes from one diploid parent cell, halving the chromosome number.
- Dominant allele
- An allele that is expressed in the phenotype even when only one copy is present, masking the effect of a recessive allele in a heterozygote.
- Natural selection
- The process by which individuals with inherited variations suited to their environment survive and reproduce more successfully, passing advantageous alleles to future generations.
- Balanced diet
- A diet containing all essential nutrients - carbohydrates, proteins, fats, vitamins, minerals, fibre and water - in the correct proportions to maintain health and energy.
- Vaccination
- The introduction of weakened or inactive antigens into the body to stimulate an immune response and produce memory cells, giving immunity against a specific disease.
- Antibiotic
- A medicine that kills or stops the growth of bacteria, used to treat bacterial infections such as tuberculosis; it is ineffective against viruses.
- Newton’s second law
- The resultant force on an object equals its mass multiplied by its acceleration (F = ma); a larger force or smaller mass produces greater acceleration.
- Mechanical advantage
- The ratio of load force to effort force in a machine (MA = load/effort); a value greater than one means the machine multiplies the applied force.
- Kinetic energy
- The energy an object possesses due to its motion, calculated as ½mv², where m is mass in kilograms and v is speed in metres per second.
- Refraction
- The bending of light as it passes from one transparent medium to another of different optical density, caused by a change in the speed of light.
- Ohm’s law
- For a conductor at constant temperature, the current is directly proportional to the potential difference across it, expressed as V = IR where R is resistance.
- Food chain
- A sequence showing the transfer of energy from a producer through a series of consumers, with arrows pointing from the organism being eaten to the one that eats it.
- Renewable resource
- A natural resource that is replenished naturally at a rate comparable to its use, such as solar energy, wind, hydroelectric power, biomass or geothermal heat.
- Controlled variable
- A factor in an experiment that is kept constant across all trials so that any observed effect can be attributed to the independent variable alone.