year 10 chemistry Flashcards
What is an atom ?
Atoms are the basic building blocks of matter.
what is a periodic table ?
A periodic table is an order arrangement of chemical elements in rows and columns.
what are the columns called ?
Each column is called a group. Each element in a group has the same number of electrons in their outer shell.
what are the rows called ?
Each row is called a period. The elements in each period have the same number of energy levels/ shells.
what are valance electrons ?
Valance electrons are electrons in the outer shell. the group number tells you the number of valance electrons.
what are electrons ?
Electrons are subatomic particles and have a negative charge and are found in the electron shells. They are very light and have almost no mass.
what are protons ?
Protons have a positive charge and are found in the nucleus.
what are neutrons ?
Neutrons have no charge and are found in the nucleus.
what is an element ?
An element is a pure substance e that cant be broken down any further. They form a single type of atom.
what is a molecule ?
A molecule is two or more atoms connected by chemical bonds.
what is a compound ?
A compound is a substance made up of two or more different elements combined in a fixed ratio, held together by chemical bonds.
what is atomic mass ?
Atomic mass is average weight of an element. It’s the number of protons and neutrons combined.
what is an atomic number ?
The atomic number is number of Protons in an element. ( In an electrically neutral atom, this will also equal the number of electrons. )
what is an electron shell ?
An electron shell is an orbit that electrons follow around an atoms nucleus.
why are Noble gases un-reactive?
Noble gases are un-reactive because they have 8 electrons in the outer shell, therefore they don’t need to react with other elements to be stable.
do noble gases form compounds?
noble gases do not form compounds, as they’re stable and don’t need to react with other elements.
what are metals ?
Metals have a lustrous appearance and are good conductors of heat and electricity. they are located on the left side of the periodic table.