Top answers

How can I increase the rate of reaction between two substances, without changing the chemicals I use?

Rate of reaction is based on collision frequency: chemicals react when molecules come into contact with each other with enough energy to react. If you want to increase the rate of reaction, you need to find ...
EG
3236 Views

For what values of x is 2x^2 - 11x - 6 > 0 ?

The first step is to factorise the equation into two brackets. In this case we get (2x+1)(x-6)Now, for this to be greater than zero we need both brackets to be greater than zero, or both brackets to be less ...
RK
Answered by Rowan K. • Maths tutor
4105 Views

When would you use perfect tense and when would you use the pluperfect?

The perfect tense is used when in English you would say something has / hasn't happened: for example, 'she has read the book', 'he hasn't finished it yet.' The pluperfect is used when in English you would sa...
AM
Answered by Anna M. • Spanish tutor
2286 Views

What are the main differences between the verbs 'ser' and 'estar'? Demonstrate your understanding with the use of examples.

While both 'ser' and 'estar' mean 'to be' in English, there are some crucial differences between both verbs which are essential to get right at any level of Spanish. There are certain 'rules of thumb' that c...
HP
Answered by Hector P. • Spanish tutor
2451 Views

Which of the following are magnetic materials? Copper, Cobalt, Carbon, Nickel

Cobalt and Nickel
EM
Answered by Elizabeth M. • Physics tutor
2471 Views