The diagram shows some organisms in an Antarctic food chain.
Sun-Algae
→ Krill
Cod
Seal -
Whale
Which BEST describes the role of krill in this food chain?
producers
decomposers
primary consumers
secondary consumers

Three cards with holes are arranged in a straight line. a light is shined through the first card’s hole and travels through all three cards. what does this tell you about light rays? a) that light is reflected b) that light is refractive c) that light travels in a straight line d) that light does not travel in a straight line

If 15 drops of ethanol from a medical dropper weight 0.60g, how many drops does it takes from a dropper to dispense 1.0ml of ethanol? the density of ethanol is 0.80g/ml

State one important difference between a physical change and a chemical change?