Atoms & Particles
What is the smallest unit of an element?
Answer: An atom.
What is the chemical symbol for oxygen?
Answer: O.
Is oxygen an element or a compound?
Answer: An element.
Ice melts. Physical change or chemical change?
Answer: Physical change.
What do we call the starting substances in a chemical reaction?
Answer: Reactants.
Which particle has a positive charge?
Answer: Proton.
What is the chemical symbol for sodium?
Answer: Na.
Is water, H₂O, an element or a compound?
Answer: A compound.
Paper burns. Physical change or chemical change?
Answer: Chemical change.
What do we call the new substances made in a reaction?
Answer: Products.
Which particle has a negative charge?
Answer: Electron.
What does the atomic number tell us?
Answer: The number of protons.
What is a compound?
Answer: Two or more different elements chemically joined.
Water boils. Physical change or chemical change?
Answer: Physical change.
In hydrogen + oxygen → water, what is the product?
Answer: Water.
Where are protons and neutrons found in an atom?
Answer: In the nucleus.
Is carbon a metal or a non-metal?
Answer: Non-metal.
Is salt water a pure substance or a mixture?
Answer: A mixture.
Iron rusts. Physical change or chemical change?
Answer: Chemical change.
What is the formula for density?
Answer: Density = mass ÷ volume.
An atom has 8 protons and 8 electrons. Is it neutral or charged?
Answer: Neutral.
An element has atomic number 12. How many protons does it have?
Answer: 12 protons.
What is the main difference between a mixture and a compound?
Answer: A mixture is physically combined; a compound is chemically joined.
Name TWO signs that may show a chemical reaction happened.
Answer: Examples: bubbles/gas, colour change, temperature change, light, new solid.
A sample has a mass of 30 g and a volume of 10 mL. What is its density?
Answer: 3 g/mL.