Search our library of GCSE questions

Top answers

All subjects

GCSE

The first four terms in a sequence are: -1, -4, -7, -10. Write an expression for the nth term of the sequence.

Answer: -3n + 2Explanation: 'n' stands for term number. The 'nth' term is a formula with 'n' in it which enables you to find any term of a sequence. This sequence of numbers changes by the same a...

Answered by Rebecca L. • Maths tutor

7184 Views

How does the reactivity of Group 1 Metals with water change down the group?

This is due to the shielding effect. When a group 1 metal reacts with water the reaction proceeds through the formation of an ionic species MOH where M is any group 1 metal. Since the species for...

Answered by Joseph G. • Chemistry tutor

4060 Views

Students placed some grass cuttings in a vacuum flask and attached a carbon dioxide sensor. Why would the carbon dioxide levels increase over a period of 20 days?

The decomposing microorganisms that contribute to the decay of the grass must respire and respiration leads to the production and release of carbon dioxide.

Answered by Georgia B. • Biology tutor

5448 Views

Expand and simplify (3 + √ 2)(5 – √ 2)

To complete this question we can use the FOIL method.

First we can multiply out the First number in each of the brackets - 3x5=15

Then we multiply the Outer numbers in each bracket - 3x-√ 2=...

Answered by Emily J. • Maths tutor

10302 Views

When do you use 'haben' and when do you use 'sein' in the perfect tense?

In the perfect tense, sentences are formed using an auxiliary / helping verb (haben or sein) and the past participle. Haben is translated as 'to have', whilst sein is t...

Answered by Chloe S. • German tutor

6436 Views