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An atom can become excited by the absorption of photons. Explain why only photons of certain frequencies cause excitation in a particular atom.

Electrons in an atom occupy discrete energy levels. An electron can only be excited to another level if it absorbs the exact amount of energy as the difference between the two levels. Therefore the energy...

Answered by Arinjay J. • Physics tutor

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Explain why potassium has a greater first ionisation energy than rubidium.

The outer electron of potassium is closer to its nucleus than the outer electron for rubidium, as it has a stronger attractive force between the electron and the potassium nucleus. The outer electron for ...

Answered by Arinjay J. • Chemistry tutor

14401 Views

How many real life examples do i need for application points?

The more real life application the merrier. Watching the news and keeping up to date with current global and domestic economic issues is a key for this exam. If you have more current and relevant examples...

Answered by Ula E. • Economics tutor

2252 Views

How many past papers should i do before the exam?

I cannot stress this answer enough, but, ALL of them. TWICE, at least. When it comes to Maths, past papers will without a doubt be the key to unlock your target grade. Success in maths comes with practice...

Answered by Ula E. • Maths tutor

18168 Views