C2.1 structue and bonding Flashcards
what are compounds
Compounds are substances in which atoms of two or more elements are chemically
combined.
outline the structure of an atom
Atom consists of PROTONS (+), ELECTRONS (-)
and NEUTRONS (no charge)
Electrons are organised on SHELLS as follows:
maximum of 2 on the first shell
maximum of 8 on the second shell
maximum of 8 on the third shell
Every atom has a tendency to give, gain or share
electrons in order to achieve full outer shell
(structure of the nearest noble gas – group 0/8)
name two types of bonding
covalent and ionic
Ionic bonding
Ionic bonding is a type of chemical bond that involves the electrostatic attraction between oppositely charged ions. These forces act
in all directions in the lattice and this is called ionic bonding.
Ions
Ions are electrically charged particles formed when atoms lose or gain electrons. This loss or gain leaves a complete highest energy level, so the electronic structure of an ion is the same as that of a noble gas - such as a helium, neon or argon.
what charge will an atom be when it gains or loses electrons
Atoms that lose electrons become positively charged ions. Atoms that gain electrons become negatively charged ions.
Metal atoms lose the electron, or electrons, in their highest energy level and become positively charged ions
Non-metal atoms gain an electron, or electrons, from another atom to become negatively charged ions
elements in group 4 bond in which way
covalent bonding
if an ion is in group 1-3(metal0 what charge will they be
Charge of Na ,Mg ,Al
The number of charges on an ion formed by a metal is equal to the group number of the metal
Na+ ,Mg2+, Al3+
electroniic configuration magnesium atom,,,,magnesium ion
mg ==2,8,2
mg2+=== [2,8]2+
electroniic configuration of chlorine atom,,, ion
Chlorine is in Group 7. It has seven electrons in its highest energy level. It gains an electron from another atom in reactions, forming a chloride ion, Cl-.
Cl 2,8,7
Cl- [2,8,8]-
what is ionic compound example==
sodium + chlorine → sodium chloride
magnesium + oxygen → magnesium oxide
calcium + chlorine → calcium chloride
When metals react with non-metals, electrons are transferred from the metal atoms to the non-metal atoms, forming ions. The resulting compound is called an ionic compound.
ionic bond.
There is a strong electrostatic force of attraction between these oppositely charged ions, called an ionic bond.
alkali metals
The elements in Group 1 of the Periodic Table are called the alkali metals. They form ionic compounds when they react with non-metals. Their ions have a single positive charge. For example, sodium forms sodium ions, Na+.
halogens
he elements in Group 7 of the Periodic Table are called the halogens. They form ionic compounds when they react with metals. Their ions have a single negative charge. For example, chlorine forms chloride ions, Cl–.
Cations anions)
Cations are positively charged ions.
Anions are negative ions
