Unit 1, Topic 3 - Bonding and Structure Flashcards
What types of substances usually form together to make ionic compounds?
Metal and non-metal
Describe ionic bonding
It is an electrostatic force of attraction between oppositely charged ions.
What can be said about the strength of ionic bonds?
They are strong
Why do atoms gain or lose electrons?
They are more stable with a full outer shell of electrons. When forming compounds atoms tend to have stable electron arrangement.
How do you work out how many electrons a metal loses when it forms an ion?
A metal loses electrons equal to the number of electrons in the outer shell.
A metal loses electrons equal to the number of electrons in the outer shell.
Why do metal ions do this?
They are more stable with a full outer shell of electrons.
What always happens when metal atoms form ions?
They lose electrons to form positive ions.
Write an equation to show how aluminium ions are formed from aluminium atoms.
Al —> Al 3+ + 3e-
2,8,3 2,8
What happens to non-metal atoms when they form ions?
They always gain electrons to become negative ions.
How do you work out how many electrons a non-metal atom gains when it forms an ion?
The number of electrons gained is the same as the number of electrons needed to fill the outer shell.
Know how to write nuclide notation for ions. E.g. How would you write the nuclide notation for a chloride ion with mass number 35?
35
Cl-
17
Know how to work out the number of protons, neutrons and electrons when given the nuclide notation of an ion. E.g. 27
Al 3+
13
protons+13
neutrons+14
electrons=10
What type of substances have metallic bonding?
Metals
Describe metallic bonding.
Electrostatic attraction between positively charged atom cores or ions and delocalised electrons.
What can be said about the strength of a metallic bond?
It is strong
What type of elements usually form covalent compounds?
Non-metal atoms
What is a covalent bond?
A shared pair of electrons
What holds the atoms together in covalent bonding?
(be able to draw diagrams)
The shared pair of electrons is attracted to both positive nuclei.
Be able to draw diagrams to show howthe outer electrons are shared in elements and compounds to from covalent bonds.
See notes and slides.
What is the formula for an oxygen molecule? How many bonds are there between atoms?
O2-2 shared pairs of electrons (we write the 2 smaller and at the bottom of the O.
What is a diatomic molecule?
A molecule that contains 2 atoms
What is a molecule?
A group of atoms held together by covalent bonds.
What are the 7 elements that exist as a diatomic molecule?
H2, O2, N2, F2, Cl2, Br2, I2