View
267
Download
0
Embed Size (px)
DESCRIPTION
Chemical Reactions
Citation preview
Chemistry
What is an atom?Atoms are the basic building blocks of ordinary
matter. Atoms can join together to form molecules, which in turn form most of the objects around you.
Atoms are composed of particles called protons, electrons and neutrons.
What is an element?An element is a substance that is
made entirely from one type of atom. If you change the number of protons an atom has, you change the
type of element it is.
Atoms and Elements
Metals
Metals Metals are opaque, lustrous elements that are good conductors of heat and electricity. Most metals are malleable and ductile and are generaly denser than the other elemental substances.
Non-metalsA non-metal is an element on the
periodic table that does not have the properties of a metal element. Non metals are usually found as gases.
Non-metals
The periodic tableWhat is the periodic table?The periodic table arranges all the known elements in an informative array. Order generally coincides with increasing atomic mass.
compounds A chemical compound is a
substance composed of two or more
different elements
chemically bonded
together in a fixed
proportion by mass.
Chemical reactionsA chemical reaction is a process that leads to the transformation of one set of chemical substances to another.
Physical reactions
A common physical change
occurs when matter changes
from one phase to another. When an ice cube melts for
example, it becomes liquid
water.