Matter Flashcards
Anything that has mass and takes up space.
Matter
The study of matter and how matter changes.
Chemistry
A single kind of matter that is pure, meaning that it always has a specific makeup or composition.
Substance
Are all types of matter substances?
No
Two examples of substances:
Salt, Water
What is matter described by?
Its properties
What are the the two kinds of properties that every form of matter has?
Physical and Chemical
A characteristic of a substance that can be observed without changing it into another substance.
Physical Property
A characteristic of a substance that describes its ability to change into different substances.
Chemical Property
Example of physical property:
The three states of water. Even though it looks different, it is still water.
Two examples of chemical property:
Iron - reacts to oxygen forming rust
Silver - reacts with sulfur in the air forming tarnish
What are the four “elements” Empedocles believed matter was made of in 450 B.C.?
Air, Earth, Fire, Water
How many elements do scientists know of?
118
What are the simplest substances?
Elements
What can each elements be identified by?
Specific physical and chemical properties
What does the particle theory explain?
All matter is made up of atoms
What are the basic particle form which all elements are made of?
Atoms
What is at the center of an atom and what is its charge?
Nucleus, positive
What surrounds the nucleus and what is its charge?
A “cloud” of negative charge
Why do elements have different properties?
Their atoms are different from each other.
When atoms combine, what do they form?
A chemical bond
What is a chemical bond?
A force of attraction between two atoms
What is a molecule?
A group of two or more atoms held together by chemical bonds.
Do molecules have to be made up of the same type of atom?
No, but they can be
What are some examples of common molecules?
Oxygen molecule -2 oxygen atoms
Water - 2 hydrogen atoms and one oxygen atoms
Carbon dioxide - 1 carbon atoms and 2 oxygen atoms
A substance made of two or more different elements that are chemically combined.
Compound
Are elements made up of different or the same type of atoms?
The same. Elements can be one atom or molecules made up of the same type of atom.
What is a chemical formula?
A statement that shows the elements in a compound and the ratio of atoms.
What is an example of a chemical formula?
C02: carbon dioxide
Are all all compounds molecules? And are all molecules compounds?
All compounds are molecules but not all molecules are compounds.
If there is no number after a element’s symbol in a chemical formula then it is understood that the number is what?
1
When elements chemically combine, do they form compounds with properties that are the same or different from the elements?
Different from the elements
What is a mixture?
Tow or more substances that are together in the same place but their atoms are not chemically bonded. Each substance in a mixture keeps its own properties.
What is a heterogenous mixture?
You can see the the different parts of a mixture and they can be easily separated out.
What is a homogeneous mixture?
You can’t see the different parts of a mixture and it would be difficult to separate the parts.
What is an example of a heterogenous mixture?
Sand
What is an example of a homogenous mixture?
Air
Can mixtures be separated?
Yes, by filtration, magnetic attraction, distillation, evaporation.
A measure of the force of gravity on something.
Weight
What instrument measures weight?
Scale
Can the same object weight differently depending on location?
Yes, you weigh less on the moon because there is less gravity.
The amount of matter in an object
Mass
Can the same object have a different mass depending on location?
No, mass is not measured by gravity like weight is
What do scientists prefer to use, mass or weight?
Mass, because it doesn’t change as a result of gravity.
What do scientists use to measure the properties of matter?
International System of Units (SI)
What is the SI unit for mass?
Kilogram (kg)
What is the amount of space that matter occupies called?
Volume
What is the SI unit for volume?
Cubic Meter (m3)
What are some common unites of volume?
cubic centimeter (cm3), liter (L)
What is the measure of the mass of a material in a given volume?
Density
Can two materials have the same weight but different masses?
Yes, because one material might be more dense than another.
How can you determine the density of a sample of matter?
Divide the mass by its volume
Density = Mass/volume
Why happens when a material has a density less than water?
It will float
Can density be used to determine the identify of an unknown substance?
Yes, if the density of an unknown substance matches the density of a known substance, it is probably that substance. Gold miners used this method.
A change in the form or appearance of matter but not ta change in what the substance is.
Physical change
Is a substance that undergoes a physical change still the same substance?
Yes
Is melting water a physical or chemical change?
Physical
Are changes in the states of matter physicals or chemical changes.
Physical
Is dissolving a physical or chemical change?
Physical
A change in matter that produces one or more new substances.
Chemical change
When a single substance breaks down into two or more other substances is it a chemical or physical change?
Chemical, Example: hydrogen peroxide broken into water and oxygen
When two or more substances combine to form different substances is it a chemical or physical change?
Chemical, Example: Photosynthesis
What are some common processes that lead to chemicial changes?
Combustion (burning), electrolysis, oxidation, and tarnishing.
How does electrolysis cause a chemical change?
Use of electricity to break a compound into elements.
How does oxidation cause a chemical change?
Combination of a substance with oxygen.
How does tarnishing cause a chemical change?
Slow combination of a bright metal with sulfur or another substance.
The fact that matter is not created or destroyed in any chemical or physical change.
Law of conservation of mass
(During a chemical change, atoms are not lost or gained, only rearranged.
What is the ability to do work or cause change?
energy
Do all chemical and physical changes in matter include a change in engery?
Yes
Give two examples of changes that require energy?
- bending a paper clip
2. ice melting
Like matter, _________ is conserved in a chemical change.
Energy
Can energy be created or destroyed?
No, it can only be transformed from one form to another
What is the measure of how hot or cold something is?
Temperature
What is temperature related to?
The energy of motion of the particles of matter.
What is the total energy of motion of all of the particles in an object called?
Thermal energy
Are temperature and thermal energy the same thing?
No, but the amount of thermal energy an object has is related to its temperature.
Where does thermal energy naturally flow from?
From warmer matter to cooler matter
What is a change in which energy is absorb called?
Endothermic change
Give an example of an endothermic change.
Ice melting in a picnic basket and cooling the food.
What is an change in which energy is given off called?
Exothermic change
Give an example of an exothermic change
Combustion (a chemical change that releases thermal energy and light)
What is the energy stored in the chemical bonds between atoms called?
Chemical energy
Where can chemical energy be stored?
Foods, fuels, and the cells of your body
Can chemical energy change into other forms of energy, and can other forms of energy change into chemical energy?
Yes, riding a bike up a hill…chemical energy from food you ate change into energy of motion
