Elements, compounds and mixtures Flashcards
what is a element?
An element is a pure substance that cannot be split into simpler substances by chemical means.
Where do do you find the elements listed?
the periodic table
What is a compound?
A compound is a a substance made up of two or more different types of atoms chemically combined.
What is a molecule?
A molecule is the smallest amount of element or compound that still has chemical properties of that element or compound.
What is a mixture?
A mixture consist of two or more different substances mingled with each other but not chemically combined.
What is an atom?
An atom is the smallest part of an element that still remains the properties the element.
What is an atom made up of?
Protons
Neutrons
Electrons
Give two properties of the atomic nucleus?
protons and neutrons
centre of the atom
how do calculate neutrons?
Atomic number - Mass number
name 2 alkali metals
Sodium
Potassium
Describe the physical properties of the alkali metal?
Soft, easy to cut.
Less dense than water
Low melting point
Describe the chemical properties of the alkali metals?
very reactive, one electron on the outer shell
Loses 1 electron in chemical reactions(forms positive ions)
