End Of Year S3 Flashcards
How are elements in the periodic table arranged?
In order of increasing atomic number
What can the periodic table be used to determine
Whether an element is a metal or non metal
What does a nucleus contain
Contains protons neutrons and electrons that orbit the nucleus
Protons charge ?
1positive
Charge if neutrons?
Neutral
Electron charge?
1 negative
What has the approximate mass of 1 atomic mass unit
Protons and neutrons
How do u know the number of protons given from an atom
Is given by the atomic number
In a neutral atom the number of electrons is eaqual to the…?
Number of protons
The mass number of an atom is equal to….?
The number of protons added to the number of neutrons
What are isotopes defined as
Atoms with the same atomic number but differnt mass numbers
What is nuclide notation used to show?
Atomic number
Mass number
Charge of atoms from which the number of protons electrons and neutrons can be determined
How many isotopes do elements normally have
1 or 2
How was the average atomic mass calculated for each element ?
And what are the values known as
By using the mass and proportion of each isotope present
These are known as relative atomic masses
What forms between non metal atoms
Covalent bonds
When do covalent bonds form ?
When 2 positive nuclei are held together b their common attraction for a shared pair of elements
What are the 7 diatomic elements
Hydrogen
Nitrogen
Oxygen
Fluorine
Chlorine
Bromine
Iodine
What does the shape of covalent molecules depend on
Number of bonds and the orientation of these bonds around the central atom
What are the 4 shapes of covalent molecules
Linear
Angular
Trigonal pyramidal
Tetrahedral
What does more than 1 forming between atoms lead to
Double or triple covalent bonds
What can covalent substances form?
Discrete molecular or giant network structures
Covalent molecular substances have strong….?
Covalent bonds within the molecules and only weak attractions between the molecules
Covalent molecular substances have low….?
Melting and boiling points as only weak forces of attraction between the molecules are broken when a substance changes state
Covalent molecular substances have a network of……?
Strong covalent bonds within one giant structure
Covalent molecular substances do not conduct…?
Electricity because they do not have charged particles which are free to move
Covalent molecular substances which are…?
Insoluble in water may dissolve in other solvents
Covalent network structures have a network of…?
Strong covalent bonds within a giant structure
Covalent network structures have very high…?
Melting and boiling points because the network of strong covalent bonds is not easily broken
Covalent network structures do not….?
Dissolve in general
Covalent network substances do not…?
Conduct electricity this is because they do not have charged particles which are free to move
When are ions formed
Ions are formed when when atoms lose or gain electrons to the stable electron arrangement of a noble gas
In general metal atoms lose……?
electrons forming positive ions and non metal atoms to gain electrons forming negative ions
What are ionic bonds .?
Are the electrostatic attraction between positive and negative ions
Ionic compounds form…?
Lattice structures of oppositely charged ions with each a positive ion surrounded by negative ions and each negative ion surrounded with each positive ions
Ionic compounds have high…?
Melting and boiling points because strong ionic bonds must be broken in order to break up the lattice
Many ionic compounds are..?
Soluble in water