Top answers

How do alveoli create a surface for efficient gas exchange?

This kind of question is extremely common in A level biology, they want you to explain a system and apply your knowledge of biological principals to it. To understand alveoli we need to understand the concep...
MC
Answered by Matthew C. • Biology tutor
8392 Views

What's the difference between 'ser' and 'estar'?

The first important thing to remember is that there is no equivalent in Enlgish, as both verbs mean 'to be'. They can also not be used interchangeably, and both have a slightly different meaning. I think the...
JS
Answered by Jack S. • Portuguese tutor
3406 Views

Find the 12th term and the sum of the first 9 terms on the following Arithmetic Progression: a = 2 and d = 3

12th term = a + (12 - 1)*d = 2 + 11(3) = 35 Sum (9) = 9/2 [2(2) + (9 - 1)*3] = 9/2 [28] = 252/2 = 126
ER
Answered by Elijah R. • Maths tutor
3797 Views

The energy of a photon is 1.5MeV. Calculate the frequency associated with this photon energy and state an appropriate unit in your answer.

E=1.5MeV = (1.5x10^6)(1.6x10^-19)J = 2.4x10^-13J E=hf, f=E/h = (2.4x10^-13)/(6.63x10^-34)=3.6x10^20Hz
TD
6123 Views

How do you do well on the paper 1 and paper 2 English literature A-level exam?

In order to do well in the exam, the first thing is to figure out the AOs, or the Assessment Objectives required in each question of your paper. Many students make the mistake of not remembering the AOs requ...
RB
Answered by Rebecca B. • English tutor
7624 Views