Elements, Compounds and Mixtures Flashcards
what is an element?
a substance that cannot be broken down into simpler substances by ordinary chemical methods
what are the two categories in which elements can be classified into?
metals and non-metals
how to classify elements on the periodic table?
staircase method
what are atoms?
the smallest particle of an element that have their same chemical properties
what are the characteristics of atoms?
- the atoms of one element are not the same as another element
- elements are made up of tiny particles called atoms
what are molecules?
a group of two or more atoms that are chemically combined together
what is the significance of molecules?
not all elements exist as atoms, most non-metals exist as molecules
what are the diatomic molecules?
- H2
- N2
- O2
- F2
- Cl2
- Br2
- I2
- At2
how to distinguish diatomic molecules on the periodic table?
do the 7+1 method
what are compounds?
a substance that contains two or more elements chemically combined together
what are mixtures?
mixtures are formed when two or more substances are added together without any chemical bonds being formed
what is the composition of a compound?
fixed composition by mass
what is the composition of a mixture?
variable composition by mass
what are the melting and boiling points of a compound?
fixed melting and boiling points
what are the melting and boiling points of mixtures?
variable melting and boiling points
