Biology
Name the organelle where photosynthesis occurs.
Chloroplast
What type of particle is negatively charged?
Electron
What is the unit of energy?
Joule (J)
A block has a mass of 2.5 kg and a volume of 0.5 m³. Calculate its density.
2.5÷0.5=5kg/m3
What is the formula for kinetic energy?
KE = ½mv²
What is the role of enzymes in the body?
What is the pH of a neutral solution?
7
What is meant by “work done” in physics?
Energy transferred when a force moves an object
A force of 50 N acts on an object with a mass of 10 kg. Calculate acceleration.
a=F÷m=50÷10=5m/s2
What is the equation for photosynthesis?
Carbon dioxide + water → glucose + oxygen
What is diffusion?
The movement of particles from an area of high concentration to low concentration
What is a mixture?
Two or more substances not chemically bonded. It contains elements and compounds.
Why do objects slow down when no force is applied to keep them moving?
Friction and air resistance act against motion
A solution contains 25 g of solute in 200 cm³. Calculate concentration.
25÷200=0.125g/cm3
What is the difference between exothermic and endothermic reactions?
Exo = releases energy, Endo = absorbs energy
Why are root hair cells adapted for absorption?
Large surface area increases uptake of water and minerals
Why do metals conduct electricity?
Delocalised electrons can move and carry charge
What is the difference between speed and velocity?
Velocity includes direction, speed does not
A wave has a frequency of 5 Hz and a wavelength of 4 m. Calculate its speed.
v=fλ=5×4=20 m/s
Explain why increasing temperature increases pressure in a gas.
Particles move faster → collide more often and harder
What is the difference between aerobic and anaerobic respiration?
Aerobic uses oxygen, anaerobic does not
Why does increasing temperature increase the rate of a chemical reaction?
Particles move faster → more frequent and energetic collisions
Why does increasing current in a wire make it hotter?
More energy is transferred → more collisions between electrons and ions → heat produced
A car accelerates from 10 m/s to 30 m/s in 5 seconds. Calculate acceleration.
a=(30−10)÷5=4m/s
Explain why increasing surface area increases the rate of heat transfer.
More particles exposed → more energy transfer → faster heat loss