Question | Answer |
Density, color, odor, texture, and solubility are all examples of what kind of property? | Physical property |
How is chemistry related to matter? | Chemistry is the study of matter and how it behaves or changes. |
Why does an object sink or float? | Its density |
What is the formula for density? | Mass divided by volume (m/v) |
What is mass? | The amount of matter (stuff) something is made of. |
What is volume? | The amount of space taken up by a substance. |
What happens to particles (molecules/atoms) when heat is added to them? | They move faster and spread out. They become less dense. |
What happens to particles (molecules/atoms) when they get colder? | They move slower and get closer together (denser). |
What happens when warm water or air runs into cold water or air? | The warm water or air rises, and the cold water or air sinks. |
Why does warm air rise? | It is less dense than colder air--its molecules are more spread out. |
What type of property are boiling point, melting/freezing point? | Physical property |
What happens to the molecules of a substance when it freezes? | They get closer together. |
What happens to the molecules of a substance when it melts? | They move faster and spread out. They also slide freely past each other. |
What are the parts of an atom? | proton, neutron, and electron |
What are the charges of an atom's parts? | Protons are positive. Neutrons are neutral. Electrons are negative. |
An atom has parts that are charged. Why is the atom not charged? | The positive parts (protons) equal the negative parts (electrons). |
What parts of an atom are involved in a chemical change? | Electrons--atoms share or give/take electrons with other atoms. This is what causes the chemical change. |
What is a molecule? | A group of two or more atoms. |
What is a compound? | A substance that is made of two or more elements. |
What is an element? | A substance made of only one kind of atom. |
What does it tell you if carbon is number 6 on the periodic table of elements? | It has 6 protons in its nucleus. |
What is conductivity? | The ability of elements to carry (transmit) heat or electricity. |
What is easier to separate, a compound or a mixture? Why? | Mixtures because their parts are not chemically bonded to each other. |
What kind of a change is burning? Why? | It is a chemical change because it creates a new substance. |
What is a reactant? | The original substances that are involved in a chemical reaction or change. |
What is a product? | The new substances that are created in a chemical change. |
The chemical change in burning a candle can be written this way:
Oxygen + Wax---------------------->Carbon Dioxide+Water
What are the reactants in burning a candle? | Oxygen and wax |
The chemical change in burning a candle can be written this way:
Oxygen + Wax---------------------->Carbon Dioxide+Water
What are the products of a burning candle? | Carbon Dioxide and Water |
What are some signs of a chemical change? | temperature change, release of light, odor change, new solid, new gas, fizzing/bubbling |
What is the Law of Conservation of Matter? | Matter cannot be created or destroyed. |
If 52 oxygen atoms go into a chemical reaction, how many will come out? | 52-the same number will always come out as what you started with. |
Rusting can be written like this:
Iron + Oxygen----------------------->Iron Oxide (rust)
What are the reactants in this rusting process? | Iron and Oxygen |