Describing Matter
Matter is defined as anything that has _______ and __________ .
1. mass
2. takes up space
A substance that cannot be broken down into any other substances
Element
An element is already in "simplest form." You can't break it apart into anything different. Elements are the building blocks for all compounds.
A measure of the force of gravity on an object
Weight
A change in matter which alters the appearance of the matter while keeping the same chemical composition
Physical change
Which of the following is an element:
Water, Iron, Carbon Dioxide, Glucose
Iron. The rest are compounds.
A single kind of matter that is pure.
Matter that is not mixed with any other matter.
Substance
A container of gold atoms would be a pure substance. If I blend in some copper atoms into the same container, it is now a mixture and is no longer pure.
The smallest particle that makes up an element
Atom
An atom is the smallest piece of a substance that can still be considered the substance. Think about ripping off the smallest possible piece of aluminum foil. That smallest piece would be an atom.
The amount of matter in an object. This number represents the amount of particles that make up an object.
Mass
Bonus: What are some of the SI units for mass?
What is one type of chemical change that occurs?
Combustion (burning), Electrolysis, Oxidation, Tarnishing
Describe 4 different ways of separating mixtures
Distillation, evaporation, filtration, and magnetic attraction
Describe the physical and chemical properties of iron.
Do the formulas H2O and H2O2 represent the same chemical compound?
No, a different ratio of atoms in a chemical formula represents a different compound with different physical and chemical properties.
Describe how you can find the volume of an irregularly shaped object.
Water displacement in a graduated cylinder
Bonus: How can you find the volume of a regularly shaped object?
This law of the universe states that matter can never be created or destroyed with any physical or chemical changes.
The Law of Conservation of Mass
The number of cubic centimeters taken up by 1 Liter.
1000 cubic centimeters.
1 L = 1000 mL = 1000 cubic centimeters
1 mL = 1 cubic centimeter
Table salt (NaCl) melts at the specific temperature of 801 degrees Celsius. Is this a physical property or a chemical property?
Physical property
Melting points describe a temperature in which a solid turns into a liquid. The matter is only changing its appearance, not its chemical composition. Therefore, the change is physical.
The easiest way to tell whether something is a mixture
Can it be separated?
Bonus: What are some methods of separating mixtures?
Maple syrup has a density that is greater than 1 g/mL.
How would maple syrup behave in water?
It will sink because water has a density of 1 g/mL.
A physical or chemical change in which energy is absorbed by the matter
Endothermic
Bonus: What would a physical or chemical change in which energy is released be called?
Why is melting point a physical property while burning is a chemical one?
When a substance melts, its chemical bonds are not changed. Changing a solid to a liquid is a change in appearance.
Burning is a chemical change because it involves changing substances into different substances (smoke, ash, etc.)
Helium is a gas which does not usually react with other substances. Does this mean that helium has no chemical properties?
Helium DOES have chemical properties. Not being able to chemically react IS a chemical property. Some substances are more reactive than others, and helium does not like to react very much.
What is the difference between a molecule and a compound?
A molecule is 2 or more atoms bonded chemically
A compound is 2 or more elements bonded chemically.
All compounds are molecules. Not all molecules are compounds. Example: O2
What is the density of an object with a mass of 125 grams and a volume of 40 mL.
Density = Mass / Volume
125g / 40mL = 3.125 g/mL
Combining baking soda and vinegar results in a chemical change that produces a new substance in the form of gas bubbles. Touching the reaction feels cold. Is this an endothermic change or an exothermic change?
Endothermic. Heat is begin absorbed by the change. The reaction feels cold because thermal energy leaves your hand and is transferred to the reaction.
Which piece of laboratory equipment would be most useful in determining the mass of an object?
Triple beam balance (scale)