Atoms & Elements
Matter & Mixtures
Solutions
Changes & Reactions
IA Challenge
100
What two particles are in the nucleus?
Protons & Neutrons
100
Is gold an element, compound, or mixture?
Element
100
In saltwater, which part is the solute?
Salt
100
Is melting ice a physical or chemical change?
Physical Change
100
What is the name of NaClO₃?
Sodium chlorate
200
What change does an electron have?
Negative
200
True or false: A mixture is a pure substance.
False
200
What do we call the substance that dissolves the solute?
Solvent
200
Is rusting iron a physical or chemical change?
Chemical Change
200
Which is a polar molecule: F₂, CO₂, CH₄, or NH₃?
NH₃
300
An atom has 14 protons. What element is it?
Silicon (Si)
300
Is evenly mixed saltwater homogeneous or heterogeneous?
Homogenous
300
What happens to the solubility of KCl as water warms from 30°C to 70°C?
Increases
300
What three quantities are conserved in chemical reactions?
Mass, energy, and charge.
300
What type of bonding has mobile electrons in tungsten metal?
Metallic bonding
400
In a neutral atom, how do protons and neutrons compare?
Equal numbers, opposite charges
400
What is one difference between a pure substance and a mixture?
Something with: # of substances or fixed composition
400
What does concentrated mean?
A relatively large amount of solute compared with solvent or solution.
400
What does a catalyst provide in a chemical reaction?
An alternate reaction pathway with lower activation energy.
400
Why does oil-and-vinegar dressing separate into layers?
It is a heterogeneous mixture; oil is nonpolar and vinegar is water-based/polar, so they do not dissolve in each other.
500
How does the modern model describe electrons?
They are on the outer layer of the nucleus
500
How can mixtures be separated, and how is this different from compounds?
Mixtures by physical methods; compounds require chemical changes to break into simpler substances.
500
How does dissolved KCl affect the boiling point of water?
The solution boils at a higher temperature than pure water at the same pressure.
500
Describe three changes and explain their types.
Example: ice melting—physical, paper tearing—physical, iron rusting—chemical. New substances form in chemical changes.
500
Compare an element, a compound, and a mixture. Give examples.
Element: one type of atom (gold). Compound: chemically bonded elements (water). Mixture: physically combined substances (salad dressing).