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To what extent was Reagan the cause of the end of the Cold War?

How to answer - 3 key words/ phrases: Extent : Asking you to pass judgement. Reagan the cause : Gives you a factor to evaluate/ compare to others. End of the Cold War : Provides direction to the question for...
RB
Answered by Rohan B. • History tutor
4713 Views

How are trends in ionisation energy explained?

Horizontal trend: First ionisation energies increase going to the right in a period. This is due to an increase in the atomic mass (and number of protons) and hence in the electrostatic attraction between th...
MC
Answered by Miruna C. • Chemistry tutor
1957 Views

How to prove that Integral S 1/(a^2+x^2) dx= 1/a arctan(x/a) + C ?

In order to answer this question, at first we need to use the method of substitution. That means, we're trying to replace x with a different variable u. Lets use the substitution of x = a tan u, then du/dx =...
JW
Answered by Judyta W. • Maths tutor
9342 Views

What is the difference between Ionic and Covalent Bonding

Ionic Ionic bonding happens between metals and non-metals. The electrons in ionic bonding are given or taken. For example, Sodium + Chlorine --> Sodium Chloride. (Na + Cl --> NaCl ) Sodium only has one...
AT
Answered by Ananya T. • Chemistry tutor
2983 Views

Describe how Giraffes evolved long necks (3)

Due to natural variation due to mutations in their DNA, some giraffes in the population had longer necks. These longer necks enabled them to reach leaves higher up on the trees, which secured them a good sou...
RS
Answered by Roshan S. • Biology tutor
4041 Views