module 8- behavior of matter Flashcards
physical change
when matter changes in appearance without changing chemical composition
chemical change
results in a change in the chemical composition
chemical reaction
when the chemical bonds are formed or broken
ex. mixing vinegar and baking soda
compounds
consists of two or more different elements attached to each other by chemical bonds.
ion
is an atom with a net electric charge.
-Losing or gaining an electron creates an imbalance of positive and negative charges and results in a net electric charge.
charge of an lithium atom
When a lithium atom loses an electron, it then has three positively charged protons and two negatively charged electrons and, therefore, a positive electric charge.
ionic bond
An ionic bond is the force of attraction between oppositely charged ions. The ions result from the transfer of one or more electrons from one atom to another.
This force is a type of chemical bond
covalent bond
Covalent bonds form because of the sharing of pairs of electrons between atoms.
-a molecule consists of two or more atoms held together by a covalent bond.
happens between non metals!
molecules
- consists of more than two atoms
-it forms when electrons are shared in a covalent bond
-not all molecules are compound
molecules are made up of atoms
periodic table reading
period=rows
group=column
metalloids
are shiny metals but have intermediate electrical conductivity and are called semiconductors
nonmetals
have electrons very tightly associated with the nucleus.
law of conservation of matter
matter cannot be created or destroyed but it can be converted from one form to another through physical or chemical changes
condensation
occurs when particles in the gas phase no longer have sufficient energy to overcome attractive forces between then and turn them into liquid
