Structure and Bonding Flashcards
Full marks for ionic dot and cross diagram?
Outer shells, square brackets, charges in the top right (+, 2-), electron configurations at the bottom (2,8,8), chemical symbol (NaCl OR Na+Cl-)
Name and describe the structure formed in ionic bonding?
What type of attraction is there between oppositely charged ions?
Ionic bonding holds oppositely charge ions together in giant structures, the giant structure of ionic compounds is very regular because the ions pack together neatly like marbles in a box.
Strong electrostatic forces of attraction act in all directions , each ion in the lattice is surrounded by ions with the opposite charge and so is held firmly in place.
Why can metals conduct electricity and heat?
Delocalised electrons can carry charge and energy and are free to move around, so they collide, passing charge from one to another
On what does the ratio of atoms in an ionic compound depend?
The charges of the ions. E.g. Calcium ions are Ca2+ and chloride ions are Cl-, so calcium chloride contains twice as many chloride ions as calcium ions and it formula is CaCl2.
If we need to multiply ions made up of more than one element to write a formula, what must be used? Use the example of calcium and hydroxide?
Brackets
Hydroxide ions are OH-
Calcium ions are Ca2+
Calcium hydroxide Ca(OH)2
What is ionic bonding?
When a metal reacts with a non-metal they transfer electrons to achieve a full outer shell.
What is covalent bonding?
Wen a non-metal reacts with a non-metal they share electrons to achieve a full outer shell.
How are the atoms in a molecule held together?
Each shared pair of electrons strongly attracts the two atoms, forming a covalent bond.
How many covalent bonds do atoms in group 6 form and why?
Group 5?
Atoms in group 6 form two covalent bonds because they need to gain two electrons in their outer shell.
Atoms in group 5 form three covalent bonds because they need to gain three electrons in their outer shell.
Why do many covalently bonded substances consist of small molecules?
As a covalent bond acts only between the two atoms it bonds to each other.
Give an example of one atom that can form several bonds, what type of structure is produced?
Carbon can form several covalent bonds, it joins together in a giant covalent structure or a macromolecule.
Describe the structure of a giant metallic structure?
The atoms are all the same size, the atoms are arranged in layers in regular patterns.
In metallic bonding what happens to the electrons in the highest energy level and what does this produce?
How is the structure held together?
When metal atoms pack together the electrons in the highest energy level delocalise and can move freely between atoms.
This produces a lattice of positive ions in a sea of moving electrons.
The delocalised electrons strongly attract the positive ions and hold the giant structure together.
