Search our library of A Level questions

Top answers

All subjects

A Level

give two features of DNA that is important for DNA replication

complementary base pairing - new strand can be synthesised based on the base sequence on the template strand, so that the resulting strand synthesised is identical to the coding strand.
hydrogen bon...

Answered by Xiaobo (Ivy) J. • Biology tutor

2614 Views

Given f(x) = 7(e^2x) * (sin(3x)), find f'(x)

f(x) = 7e^2x sin(3x) Chain rule: f(x) = uv → f'(x) = u'v + uv' u = 7e^2x u' = 14e^2x v = sin(3x) v' = 3cos(3x) f'(x) = 14e^2xsin(3x) + 7e^2x 3cos(3x) f'(x...

Answered by Chris K. • Maths tutor

4127 Views

Differentiate y=x^3+ 7x-ln(2)

Dy/dx=3x²+7

Answered by Shrey J. • Maths tutor

3291 Views

State and explain the general trend in the first ionisation energies of the Period 2 elements Lithium to Fluorine.

The general trend is that the first ionisation energies increase across the period.First ionisation energies increase across the period as from Lithium to Fluorine the nuclear charge is increasing yet the...

Answered by Alice M. • Chemistry tutor

5738 Views

Explain why the first ionisation energy of barium is less than the first ionisation energy of calcium.

Barium is in the sixth period, Calcium is in the fourth. Therefore, Barium experiences more shielding, resulting in weaker attraction of the nucleus for outermost electrons.

Answered by Joseph F. • Chemistry tutor

5359 Views