Describing Matter
Give 3 examples of an element.
Many answers: oxygen, hydrogen, carbon, aluminum, lithium, sulfur, boron, etc.
What is the formula for calculating volume of a rectangular prism?
V = L x W x H
Give two examples of a physical change.
Any change in states of matter (solid to liquid, liquid to gas, gas to solid), dissolving, cutting potato
What happens to chemical energy during a chemical change?
During a chemical change, chemical energy may be changed to other forms of energy. Other forms of energy may also be changed to chemical energy.
What is matter?
Matter is anything that has mass and takes up space
What is the difference between chemical and physical properties?
Physical properties can be observed without changing a pure substance into another substance, while chemical properties can only be observed by trying to change one pure substance into another substance.
How are millilitres (mL) related to cubic centimetres (cm3)?
1 mL = 1 cm3
Give two examples of a chemical change.
Combustion, electrolysis, oxidation, tarnishing
Where is chemical energy stored?
It is stored in the chemical bonds between atoms.
What is the law of conservation of mass?
This law states that matter is not created or destroyed in any chemical or physical change.
Does H2O2 and H2O represent the same compound? Explain why or why not.
No because the ratios of the elements in these two chemical formulas is different. That means that they are different compounds.
Extra info: H2O is the chemical formula for water. H2O2 is the chemical formula for hydrogen peroxide.
What is the formula for calculating density?
Density = m/V
Give an example of an exothermic change.
Combustion is an example of an exothermic change. When you light a candle, energy is being released in the form of heat and light.
What are the 6 forms of energy related to changes in matter?
Thermal energy, kinetic energy, potential energy, chemical energy, electromagnetic energy, and electrical energy
What is oxidation? Give an example.
Oxidation is the slow combination of a substance with oxygen.
Ex: iron rusting
How are elements and compounds similar? How are they different?
Both elements and compounds are pure substances. Elements are not made of simpler substances (they are made out of atoms), compounds are made up of two or more elements that are chemically combined.
How can you determine whether a solid object is more or less dense than water?
If the object floats on the water, that means it is LESS dense than water.
If the object sinks, that means it is MORE dense than water.
Give an example of an endothermic change.
Ice takes in energy (in the form of heat) and will melt into a liquid.
Give 2 examples of kinetic energy and 2 examples of potential energy.
Kinetic energy: person walking, a soaring baseball, a crumb falling from a table
Potential energy: stretching an elastic band, drawing a bow, a book resting on a desk, diver climbing up a diving board
Give an example of a physical property.
Colour, taste, dullness
What are the 4 techniques for separating a mixture?
1. Using a magnet
2. Filtering the mixture with filter paper and water
3. Distilling a liquid solution
4. Evaporation
The density of tin is 7.3g/cm3 and its mass is 277g. What is its volume?
Density = m/V
V = m/Density
V = 277g / 7.3g/cm3
V = 37.9 cm3 ≐ 38 cm3
What is the difference between heterogenous and homogenous mixture? Give an example for both.
Heterogenous: you can see the different components in the mixture (ex: oil and water)
Homogenous: you cannot see the different components in the mixture (ex: coffee with milk)