Structure & Bonding Flashcards
How do atoms achieve stable structures?
Sharing or transferring electrons to form ions or molecules
What is a covalent bond?
Bonding by sharing electrons between non-metallic elements
When are ionic compounds formed?
When metallic and non-metallic elements transfer electrons to each other
What type of ions do metals form?
They lose electrons to form Positive ions
What type of ions do non-metals form
The gain electrons to become negative ions
What is an ionic bond?
The electrostatic force of attraction between positively and negatively charged ions
How many electrons do elements in group 7 have in their outer shell
7
How many electrons do elements in group 1 have in their outer shell
1
Explain what happens to the atoms when the atoms of an elements when lithium and fluorine react
Lithium loses an electron to form a lithium ion with a positive charge Li+, fluorine atoms gain an electron to form a Florida ion with a positive charge F-
What is a compound?
2 or more elements chemically combined
What are ionic compounds like?
Giant structures made of ionic bonds which holds oppositely charged ions together
What are the giant ionic structures like?
Very regular as all the ions pack together neatly
In which direction do electrostatic forces of attraction act?
All directions
Each ion in the giant structure or ……… Is surrounded by ions with the ………. Charge
Lattice
Oppositely
How are the sodium and chlorine ions arranged in the ionic compound, sodium chloride?
They alternate to form a cubic lattice but still have equal numbers of each ion
What does the ratio of ions in a structure depend on?
The ratio depends on the charges of the ions
If calcium ions have a charge of Ca2+ and chloride ions are CL- what would the formula of calcium chloride be?
CaCl2
What is used to represent the atoms and ions involved in forming ionic bonds?
Dot and cross ions
What is the charge of an ionic compound?
They are neutral
How can you work out the formula of an ionic compound?
Balancing the charges ( for every Na+ ion there is one Cl-
How is the charge of a transition metal shown?
The Roman numeral eg Iron(II)
How can you work out the charge of ions?
The group number
How do you form the formula of an ionic compound is one of the ions contains more than one element?
Brackets must be used eg Ca(OH)2
What does the formula of an ionic compound represent?
The simplest ratio of the ions in the compound and does not represent a molecule
What is a covalent bond?
The attraction between 2 atoms that share one or more pairs of atoms
What are substances held together with covalent bonds called?
Molecules
Atoms of group 7 need to gain ….. Electron do form a ………. Covalent bond
1
Single
Atoms of group 6 need to gain ….. Electron do form a ………. Covalent bond
2
Two
What are giant covalent structures like carbon called?
Macromolecules
What are the atoms in a metallic element like?
They are all the same size
What are metallic giant structures like?
The atoms are arranged in closely packed layers in regular patterns
What happens when metal atoms pack tightly together?
The electrons I the highest energy level delocalise and can move freely between the atoms
What is produced when the elections in the highest energy level delocalise?
A lattice of positive metal ions in a sea of delocalised electrons
How is a metallic structure held together?
There is electrostatic forces of attraction between the delocalised electrons and the positive metal ions
Explain why silicon (group 4) has a giant structure?
Silicon atoms form 4 covalent bonds each silicon atom, can join to four others the bonds are strong; this continues so that a giant structure is formed
