Atoms, Elements, Compounds and Mixtures Flashcards
what is an atom?
The smallest particle of a chemical element that can exist.
what is an element?
is a substance that is made up of only one type of atom and cannot be broken down.
what is a compound?
a substance made out of 2 or more different elements that are chemically joined.
what is a mixture?
a mixture is made up of 2 or more substances that is not chemically joined.
out of atoms, elements, compounds and mixtures which has the smallest particles?
atoms
Which statement about atoms and molecules is correct?
Elements always exist as separate atoms
Elements always exist as pairs of atoms called molecules
Elements and compounds can exist as molecules
Elements and compounds can exist as molecules. (Only a few elements exist as pairs of molecules).
How many different atoms are there in a compound?
2 or more
Approximately how many elements are there?
100
Which one is a compound?
Water
Hydrogen
Helium
water
How many atoms are there in total in a molecule of sulfur trioxide, SO3?
four
Why does air not have a definite formula?
Air is a mixture, so it doesn’t have a definite formula. (The amount of water vapour is not as important).
