Element
a substance that cannot be broken down into any other substances by chemical or physical means. They are the simplest substances.
Atom
The basic particle from which all elements are made. It has a positive charged center, or nucleus, containing smaller particles. The nucleus is surrounded by a "cloud" of negative charge. The elements have different properties because their atoms are diff
Chemical Bond
formed when atoms combine; a force of attraction between two atoms.
Molecule
a group of two or more atoms held together by chemical bonds.
Compound
a substance made of two or more elements that are chemically combined in a set ratio. Represented by a chemical formula.
Chemical Formula
shows the elements in the compound and the ratio of atoms. Representation of a compound.
Mixture
made of two or more substances that are together in the same place, but their atoms are not chemically bonded.
If there is no number after an element's symbol, what is the number understood to be?
One
Formula for Carbon Monoxide
CO
How are mixtures different from compounds?
Each substance in a mixture keeps its own properties. Also, the parts of a mixture are not combined in a set ratio.
What are the two types of mixtures?
Heterogeneous and homogeneous
Describe heterogeneous mixture.
you can usually see the different parts and they can easily be separated out. (ex: sand)
Describe homogeneous mixture.
so evenly mixed that you can't see the different parts. It is difficult to separate the parts of a homogenous mixture. (ex: air)
Homogeneous mixture -
solution which can be a liquid, gas or solid.
Can a mixture be separated?
Yes, because a mixture keeps its properties.
Describe the basic particle from which all elements are made.
Atoms which is made of protons, electrons, and neutrons.
How are elements and compounds related?
a compound is two or more elements.
What is the difference between a chemical symbol and a chemical formula?
A chemical symbol is an abbreviation.
A chemical formula shows the elements in the compound and the ratio of atoms.
What are two ways in which mixtures differ from compounds?
1. Mixtures are not chemically combined.
2. Mixtures keep their own properties and is not combined in a fixed ratio.
List four methods that can be used to separate mixtures.
1. Magnet attraction
2. Evaporation
3. Filtration
4. Distillation
Chemical Symbol
elements represented by one- or two-letters.