Atomic Structure and Periodic Table Flashcards
Why is Indium malleable?
- Contains layers that can slide past each other
State the name given to a reaction in which heat energy is transferred to the surroundings.
Exothermic
Why do all atoms of bromine have the same chemical properties?
Same number of electrons in outer shell
What is relative atomic mass ?
The mass of all isotopes of an atom of an element / 1/12th of mass of carbon atom - 12.
Suggest, with a reason, which of the atoms Br-79 and Br-81 exists in greater numbers in a sample of Bromine.
Br - 79 as it is closer to the RAM - 79.9
Why are atoms neutral?
Atoms are neutral because they have the same number of electrons and protons
Why are noble gases not reactive?
- They have a full outer shell
- Noble gases don’t easily lose/gain electrons
Why do lithium, sodium, and potassium all have similar chemical properties?
- All in group 1
- They all have the same number of electrons in the outer shell
A scientist dissolves a sample of boron trioxide in a beaker of water. A solution forms. Suggest a value for the pH of the solution. Give a reason for your answer.
- The solution would have a pH of (e.g. 4 any value less than 7) because boron oxide is a non-metal oxide and non-metal oxides are acidic
Describe the reactivity in group 1
- The reactivity increases as you go down the group
- This is because the elements are increasing in number of shells
- The outer electron is further away from the nucleus
- There is less attraction between the nucleus and the outer electron
- Therefore, it can be easily lost
Describe the reactivity in group 7
- Reactivity decreases as you go down
- This is because there are more electronic shells and need to gain one electron by the nucleus which is hard as the electronic shells are further away from the nucleus
Describe what you would observe when orange bromine water is added separately to ethane and ethene, in the absence of UV light.
Observation with ethane:
- No change in colour
Observation with ethene:
- Orange to colourless
Small pieces of lithium and potassium are added to separate large troughs of water.
State one observation that would be similar for each element, and one that would be different for each element.
Similar: Fizzing
Different: Potassium sparks
Explain why potassium sulfide conducts electricity when molten.
Ions are free to move
What is meant by the term inert?
Unreactive
Why are noble gases inert?
They don’t easily lose/gain electrons
OR
They have a full outer shell
What is an atom?
An atom is the smallest piece of an element
What is a molecule?
A molecule is formed when atoms join together by chemical bonds
Elements are arranged in order of _____ number and so that elements with _____ properties are in columns, known as ______.
atomic, similar, groups
Elements in the same periodic group have the same amount of _______ in their _________, which gives them similar chemical properties.
electrons, outer shells
elements with the same number of shells of ______ are arranged in rows called ________
electrons, periods
the electronic configuration of an element tells you how many ________ are in each ______ around an _______
electrons, shell, electron’s nucleus
● If an element is ________ and its oxide is _______ then the element is a metal
conductive, basic
● If an element is not _________ and its oxide is _______ then it’s a non-metal
conductive, acidic
What is the group number?
gives the number of electrons in the outer shell e.g. group 3 has 3 electrons in the outer shell
What is the period number?
gives the number of electron shells e.g. period 1 has 1 shell of
electrons
