an element contains just one type of atom a compound contains two or more types of atom joined together a mixture contains two or more different substances that are not joined together the ...

An overview of the definitions of different types of chemicals, how chemicals can be represented in chemical equations, how chemicals can be separated, and a number of important calculations ...

Smoking can increase the risk of heart disease diabetes and many other chronic conditions Experts believe it is also responsible for 12 different cancers Here’s all you need to know ...