Element, Compound, Mixture

Alyssa Slayden

Element Definition

Element- A substance that can not be broken down by chemical means.

1) Helium

Compound Definition

Compound- A substance that is formed by the chemical union of two or more elements

1) H2O= Water

When An Element Forms A Compound...

It loses its properties as it is being combined with another element to form a substance.

It has a completely different set of physical and chemical properties than the elements that formed it.

Since it is being separated back to the origional elements those elements will keep their own unique attributes.

How Are Compounds Formed and Separated?

Compounds can be formed from chemical reactions.

Compounds can be seperated by breaking the bonds between atoms.

Elements on the other hand can not be separated, they are already as simple as you can get.

Contrasting Elements and Compounds

Similarities: 1. At the lowest levels elements and compounds are both composed of atoms; 2. Compounds and elements are both pure substances that cannot be separated by physical means; and 3. Elements and compounds are homogeneous in that they have the same composition ratio of elements throughout the sample.

Differences: Elements are the simplest forms of matter- Compounds are substances that can be separated into simpler substances

Chemical Formulas Definition

Chemical Formula- Is a way of expressing information about the atoms that make up a particular chemical compound.

H2+O---> H2O

Na+Cl---> NaCl

Subscripts and Co-Efficients

Co-Efficient: A numerical constant that is a measure of a property of a substance.

Subscripts: A character that is printed on a level lower than the rest of the characters on the line

Examples: C.E. ---> 2H2(<Subscript)O

How To Count Atoms

The chemical formula lists the symbol of each element within the compound followed by a number. The letter and number indicate how many of each type of element are in the compound. If there is only one atom of a particular element, then no number is written after the element.