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Chemistry
A Level

Define the term enthalpy of reaction

A chemical reaction occurs when bonds are broken and formed between atoms. Energy is taken in in order to break bonds; when a bond is formed the molecule becomes more stable, so energy is given out. The e...

HK
Answered by Harry K. Chemistry tutor
2498 Views

Why do elements give off coloured light when heated?

When elements are heated, it causes their electrons to become excited. Electrons exist in discrete energy levels, and these energy levels are unique to each element. When the electrons are excited by heat...

GC
Answered by Gemma C. Chemistry tutor
13302 Views

Why are zinc and Scandium not transition metals?

A transition metal is defined as an element that forms a stable ion with incompletely filled d orbitals. Scandium forms a 3+ ion with no electrons in its d orbitals and zinc forms a 3+ ion with completely...

EO
Answered by Ellie O. Chemistry tutor
28171 Views

Explain what is meant by Enthalpy

In nature, when 2 elements react, energy is taken in to break bonds and energy is given out to form new bonds. The net change in heat energy during a reaction at constant pressure is called the enthalpy c...

AP
Answered by Avishek P. Chemistry tutor
1820 Views

Explain the 3 pieces of evidence that disprove Kekule's model of benzene.

Kekulé's model of benzene is that it has 3 double bonds, in a ring of 6 carbons.
One - Benzene isn't very reactive, so if Kekulé's model were to be correct, there would be 3 double bonds in benzene, ...

EW
Answered by Ellie W. Chemistry tutor
31352 Views

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