Structure and bonding Flashcards
What are atoms?
What elements are made from. An atom consists of a nucleus containing protons and neutrons surrounded by electrons.
What are ions?
Ions are electrically charged particles formed when atoms lose or gain electrons. They have the same electronic structures as noble gases.
What’s an electron?
An electron is a very small negatively charged particle found in an atom in the space surrounding the nucleus.
What form positive ions and what form negative ions?
Metal atoms form positive and non metal atoms form negative ions.
What are ionic bonds?
The strong electrostatic forces of attraction between oppositely charges ions.
Ionic compounds have _____ melting and boiling points.
High
What’s an ionic compound?
An ionic compound occurs when a negative ion joins with a positive ion. The ions swap electrons to achieve a full outer shell.
What’s a negative ion?
An atom that has gained an electron.
What’s a positive ion?
An atom that has lost an electron.
What do metal atoms do?
They lose the electron in their highest energy level and become positively charged ions.
What do non metals atoms do?
They gain an electron from another atom to become negatively charged ions.
What’s a covalent bond?
A covalent bond between atoms forms when atoms share electrons to achieve a full outer shell of electrons. This is between atoms of non metallic.
Fill gaps:
When metals react with non-metals, _________are transferred from the metal atoms to the non metals atoms, forming ______.
This resulting an _______ __________.
Electrons
Ions
Ionic compound
Why does it take a great deal of energy to separate the positive and negative ions in a crystal lattice?
Because of the strong electrostatic forces between them.
Why don’t solid ionic compounds conduct electricity?
Because the ions are held firmly in place they cannot move to conduct the electric current.
What happens to an ionic compound when it melts?
The charged ions are free to move
What happens when a crystal of an ionic compound dissolves in water?
The ions separate, and again the ions are free to move ,so a solution of an ionic compound in water also conducts electricity.
Why do ionic bonds have high melting and boiling points?
Ionic bonds are very strong so a lot of energy is needed to break them.
How can you tell that the compound h2o has covalent bonds?
It’s made up of non metals.
Explain what happens to the atoms of the elements when lithium reacts with fluorine.
Lithium atoms lose an electron to form a lithium that has a positive charge. Fluorine atoms gain an electron to form a fluorine that has a negative charge.
Metal atoms______ electrons to become stable forming ______ ions.
Lose
Positive
Non metal atoms ______ electrons to become stable forming ________ ions.
Gain
Negative
Group one charge
+1
Group two charge
+2
Group three charge
+3
Group five charge
-3
Group six charge
-2
Group seven charge
-1
What is formed when two or more elements react together?
Compounds
To achieve stable electronic structures what do the atoms of elements do?
They join together by sharing electrons or by transferring electrons to achieve stable electronic structures.
What group have stable electronic structures?
Noble gases
Fill in the gaps:
When atoms of non-metallic elements join together by sharing electrons it is called ________ __________.
Covalent bonding
How can you tell that the compound H2O has covalent bonds?
It is made up of non metals
What’s the name of the compound produced when a metallic element reacts with a non metallic element?
Ionic compounds
In ionic compounds what happens to the metal atoms?
They lose electrons to form positive ions
In ionic compounds what happens to the non metal atoms?
They gain electrons to form negative ions
Fill in the gaps:
The ions have the _________ electronic structure of a noble gas.
Stable
Fill in the gaps:
The oppositely charged ions attract each other in the ionic compound and this is called _________ ____________.
Ionic bonding
Which of these compounds have ionic bonding?
KBr, HCl, H2S, Na2O, Cl2O, MgO
KBr, Na2O, MgO
How many electrons are in the atoms of elements in group 1?
One electron in outer shell
What is the electronic structure of sodium?
2.8.1
Give the ion and electronic structure of sodium
Na+ , 2.8
How many electrons are on the outer shell of group 7 elements?
7 electrons on outer shell
Give the ion and new electronic structure of chlorine
Cl-
2.8.8
Give the formula of sodium chloride
NaCl
Explain what happens to the atoms of the elements when lithium reacts with fluorine.
Lithium atoms lose an electron to form a lithium ion that has a positive charge or Li+ , fluorine atoms gain an electron to form a fluorine ion that has a negative charge or F-
How are ionic compounds held together?
By strong forces between the oppositely charged ions. This is called ionic bonding.
Fill in the missing gap:
Ionic bonding holds oppositely charged ions together in _________ __________.
Giant structures
Why is the giant structure of ionic compounds very regular?
Because the ions all pack together neatly like marbles in a box.
Where do strong electrostatic forces of attraction act in?
In all directions
What is each ion in the giant structure or lattice surrounded by?
By ions with opposite charge and so is held firmly in place.
What does the ratio of ions in the structure of an ionic compound depend on?
On the charge on the ions.
How can we represent ions and atoms?
Using/drawing a dot and cross diagram.
Why is the formula of sodium chloride NaCl but magnesium chloride is MgCl2?
Sodium ions have a single positive charge (Na+) and magnesium ions have a double positive charge (Mg2+)
Chloride ions have a single negative charge.
What are dot cross diagrams used for?
Used to represent the atoms and ions involved in forming ionic bonds.
What shell do we show in dot cross diagrams?
The outer shell
What do the charges on ions in an ionic compound do?
Always cancel each other out
What does the formula of an ionic compound show?
It shows the ratio of ions present in the compound.
What’s the relative charge for proton, neutron and electron?
Proton: +1
Neutron: 0
Electron: -1
What’s the formula of an chlorine ion?
Cl-
What’s the formula of a magnesium ion?
Mg2+
What’s the formula of the ion phosphorus?
P3+
What’s the electronic structure of the ion chlorine?
(2.8.8)-
What’s the electronic structure of the ion magnesium?
(2.8)2+
What’s the electronic structure of the ion phosphorus?
(2.8.8)3-
Fill in the gaps:
When sodium reacts with chlorine, sodium ________ an electron and chlorine _________ an electron. When sodium atoms become sodium ions this is called __________. When chlorine atoms become __________ ions this is called _________.
Loses Gains Oxidation Chloride Reduction
Why do ionic compounds have high melting points?
There’s strong ionic bonds between the ions so they require a large amount of energy to break.
Describe under what circumstances ionic substances do and do not conduct electricity?
Do- when the substances dissolved in water and when the substance is melted/molten this is because the ions have more space to move.
Don’t - when they are solid because the ions aren’t free to move around.
Why are ionic substances brittle?
The forces align with the same charge, and the ions repel and as a result break.
Would you expect calcium oxide to have a higher or lower melting point than potassium fluoride?
Yes, I would expect the calcium oxide to have a higher melting point than KF , because the charges are double positive and double negative, this will mean that the electrostatic forces between Ca and O will be much stronger than K and Br.
How are calcium and chlorine combined what type of compound?
Ionic bonding because calcium is a metal and chlorine is a non metal.
How are carbon and oxygen bonded- what bond?
Covalent, because carbon and oxygen are both non metals.
When a metal and non metal transfer electrons forming ions what type of bonding is this called?
Ionic bonding
How do two or more non metals share electrons?
Covalent bonding
Why do atoms bond?
To get stable electron arrangements.
Fill in the gaps:
Metal atoms ________ electrons to become stable forming __________ ions.
Lose
Positive
Fill in the gaps:
Non- Metal atoms ________ electrons to become stable forming __________ ions.
Gain
Negative
Give the charge of groups 1,2,3,4,5,6,7,0
Group1: +1 Group2: +2 Group3: +3 Group 4 don't usually form ions Group5: -3 Group6: -2 Group7: -1
To cancel each other out, on the positive and negative ions what has to be the same?
The electrons lost must equal the electrons gained.
What are the charges of carbonates?
CO32-
