List 4 non-metals.
oxygen, nitrogen, hydrogen, carbon, helium, phosphorous, sulfur, chlorine,...
There are 4 cups of water with temperature of 20°C, 60°C, 80°C and 95°C. Which water in which the particles move fastest? Why?
95°C (highest), because of highest energy
The interaction between particles in an ice cube is weaker than that in water. True or False
False. It is stronger.
Why is Gold used for various types of jewellery?
Because it is shiny and malleable
List 4 properties of non-metals.
dull, brittle, do not conduct electricity, do not conduct heat well
A solution with a higher concentration (concentrated) has (more/less) solute particles compared to a solution with a lower concentration.
more
Which solution is the most concentrated in the 4 solutions? Explain your answer.
Z, because solution Z has the largest amount of solute.
Why is steel used to build house and bridge, not pure iron?
Because alloy is stronger and harder than pure metal.
Peter adds 40mL of milk into 50mL of water to make solution X. What are the solute, solvent and solution in this case?
initial milk = solute, water = solvent, diluted milk = solution
Describe the diagram of water cycle (name the terms and describe them).
evaporation, condensation, precipitation, collection
Bronze, an alloy of copper and zinc, is used to make strong, durable coins. T or F?
F: bronze (copper and tin)
When heating a solid, do the particles move faster to form a liquid or move move less and get closer together to form a liquid?
The particles move faster to form a liquid.
True of False: Metals like gold, silver, iron and copper are commonly used in electrical wiring.
F
List 5 properties of metals.
Sonorous, ductile, malleable, shiny, conduct heat and electricity
Solution X has 5g of sugar and 85g of water to produce 100g solution X. How can we prepare a higher concentration solution than solution X?
List 5 metals.
mercury, iron, gold, silver, aluminium, copper, zinc, tin, ...
Why is alloy stronger and harder than pure metal?
Because particles has a regular pattern so the particles are easy to slide, but they cannot do that in alloy because there are different types of atoms in alloy
A solution with a lower concentration (diluted) has (more/less) solute particles compared to a solution with a lower concentration.
less
Peter adds 2g of brown sugar to 50mL of water to make solution X. Then, he adds 10g of brown sugar into the solution X to get solution Y. Which solution is more concentrated? Why? How does it look like?
Y. Solution Y is darker. Because solution Y has more water particles (more solute) than solution X.
Both iron and oxygen are ductile. True of False?
False