1-1 Describing Matter
What is matter?
Matter is anything that has mass and takes up space
What are elements? What are elements made of?
An element is a substance that cannot be broken down into any other substances by physical or chemical means. Atoms are the basic particles from which all elements are made.
What is the unit for mass? How is mass different than weight?
The unit for mass is the kilogram (kg). Weight is a a measure of the force of gravity on you, so it changes depending on what gravity is. Mass is the amount of matter that is in an object, so it always remains the same.
What is a physical change?
A physical change is a change that alters the form or appearance of matter but does not turn any substance in the matter into a different substance.
What is a substance?
A substance isa single kind of matter that is pure. This means that it always has a specific makeup, or composition.
What is a molecule? What holds molecules together?
A Molecule is a group of two or more atoms that are held together by chemical bonds.
What is the volume of a box that has a width of 6m, length of 2m, and a height of 10m?
120m2
What is a chemical change?
A chemical change is any change that produces one or more new substances.
Define what a physical property is. Give two physical properties of a wooden log.
Physical properties are characteristics of a substance that can be observed without changing it into another substance.
What is the difference between a homogeneous mixture and a heterogenous mixture?
In heterogenous mixtures, you can usually see the different parts and they can be easily separated out.
In homogenous mixtures, the substances are so evenly mixed that you cant see the different parts.
What is density?
Density is a measure of the mass of a material in a given volume.
What is the law of conservation of mass?
The law of conservation of mass states that matter is not created or destroyed in any physical or chemical change. The mass of any reaction remains the same before and after the change.
Define what a chemical property is. Give one chemical property of a wooden log.
Chemical properties are characteristics of a substance that describes its ability to change it into another substance.
What are the atoms in the compound dinitrogen monoxide? How many of each atom are there?
dinitrogen monoxide has 2 nitrogenatoms and 1 oxygen molecule.
What is the density of an object with a mass of 100kg and a volume of 80m2? Will this object sink or float in water?
The object's density would be 1.25 kg/m2. It would sink in water because its density is greater than water's density of 1 kg/m2
What is the difference between an endothermic change and an exothermic change?
Endothermic changes absorb energy and often make their surroundings cold.
Exothermic changes release energy and often release thermal energy and light