Chemistry- compounds (year 9) Flashcards
What happens when elements react?
Atoms combine with other atoms to form compounds
What are compounds?
substances formed from 2 or more elements. they are held together by chemical bonds
What does making bonds involve?
atoms giving away, taking or sharing electrons
What do ions consist of?
a compound which is formed from a metal and a non metal
What do the metal atoms do?
they lose electrons to form positive ions
What do the non metals do?
they gain electrons to form negative ions
What does the opposite charges of the ions mean?
It means that they are strongly attracted to eachother
What is it called when ions are strongly attracted to eachother?
Ionic bonding
What does a compound formed from non metals consist of?
Molecules
What is it called when each atom shares an electron with another atom?
covalent bonding
What can compounds be represented by?
Formulas
What are formulas made up of?
elemental symbols in the same proportions that the elements can be found in the compounds
What is carbon dioxide formed from?
a chemical reaction between carbon and oxygen. Contains 1 carbon atom and 2 oxygen atoms
