Chemistry "need to knows"

Chemical News 4 Kids

Elements, Compounds, and Mixtures

Elements & Compounds

Element- a pure substance that cant be separated into simpler substance( ex: Hydrogen)
Compound- 2 or more elements chemically combined( ex: H20- water)
When compunds are formed, the element properties are usually not present in the new compound. In other words, the properties of the compound and the elements that formed it are different. Whenever elements are combined into a mixture, they lose their properties. In some cases, it is possible to revive them back to the original form. Some ways or methods that scientists use to separate compounds include exploiting some property that distinguishes the components( size, density, solubility, electrical charge, etc.). On the other hand, elements are impossible to separate as mentioned in the definition above, ELEMENTS ARE A PURE SUBSTANCE THAT CANNOT BE SEPARATED INTO SIMPLER SUBSTANCES. Compounds are formed by chemical reactions from simpler substances.

Simmilarities and Differences between Elements and Compounds

Simmilarities- consists of at least one or more element(s), has individual properties, associates with the periodic table and chemistry
Differences- elements can't be separated while compunds can, elements are only consisted of 1 element while compounds have more,

Chemical Formulas

Chemical Formula

Chemical Formula-   way of expressing information about atoms that constitute a particular chemical compound( ex: C6H12O6, CH3CH3,etc)

Coefficients and Subscripts

Coefficients- numbers or etc. put in front of a compound or element to help balance out equations (ex: 2O3, etc)
Subscripts- numbers or etc. put in back usually with parenthesis tohelp balance out equations ( ex: (Al)3, etc.)

Counting Atoms and Elements

The start of a capital letter will always refer to an element in a chemical formula. There will either be nothing or a small number at the end of each element. This part shows you the number of atoms. If there is no number, that means there is only one, that single standing atom/element. You just need tocount the total number and there will be obstacles including parenthesis with distributive properties and much more. Good luck!