Chemical Reactions
Q: Name an acid and an alkali used in school labs.
A: Hydrochloric acid and sodium hydroxide.
Q: What is a variable? Name 1 type.
A: Something you change, measure, or keep the same. E.g. Independent variable.
Q: What is a gene?
A: A section of DNA that codes for a protein.
Q: What type of wave is sound?
A: A longitudinal wave.
Q: What circuit has only one path for current?
A: A series circuit.
Q: What colour does litmus paper turn in acid and alkali?
A: Red in acid, blue in alkali
Q: What type of graph do you draw for continuous data?
A: A line graph.
Q: Where are chromosomes found?
A: In the nucleus of a cell.
Q: What happens to wavelength if frequency increases?
A: It gets shorter.
Q: Draw the symbol for a cell and a switch. (Just say you can sketch or describe it.)
A: A cell: long line and short line. A switch: break in line with dot and line.
Q: What is neutralisation? Give the general word equation.
A: It’s a reaction between an acid and an alkali. Acid + Base → Salt + Water.
Q: What are the independent and dependent variables?
A: Independent: what you change. Dependent: what you measure.
Q: What’s the difference between genotype and phenotype?
A: Genotype is the genetic code; phenotype is the physical expression.
Q: Describe what happens when a wave is reflected.
A: It bounces off a surface at the same angle it hits it.
Q: What is the difference between series and parallel circuits?
A: Series has one loop; parallel has multiple paths.
Q: Explain why indigestion tablets are used and how they work.
A: They neutralise excess stomach acid to relieve discomfort.
Q: A student gets an odd result that doesn’t fit. What should they do?
A: Identify it as an anomaly and repeat the experiment.
Q: What do dominant and recessive alleles mean?
A: Dominant alleles show even if one copy is present; recessive need two copies.
Q: What is the amplitude of a wave?
A: The height from the middle to the crest or trough.
Q: What happens to brightness if more bulbs are added in series vs. parallel?
A: In series: dimmer. In parallel: brightness stays the same.
Q: Who developed the periodic table and how was it organised?
A: Dmitri Mendeleev arranged elements by atomic mass and predicted missing ones. (Y8)
Q: What’s the difference between accuracy and reliability?
A: Accuracy is how close results are to the true value; reliability is how consistent they are.
Q: Two parents have brown eyes but a child has blue eyes. Explain how.
A: Both parents carried the recessive blue allele; child inherited both.
Q: Explain what diffraction is and where we see it in real life.
A: It’s the spreading of waves around obstacles; e.g., sound bending through a doorway.
Q: What group is helium in and why is it unreactive? (Y8 link)
A: Group 0; it has a full outer shell, so it's stable and unreactive.