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1. Why does the first ionisation energy of atoms generally increase across a period?

As you go across the period, the number of protons increases, however the amount of shielding stays the same, so attraction of outer electrons to nucleus increases and more energy is required to remove an el...
SA
Answered by Safia A. • Chemistry tutor
5151 Views

How to calculate the integral of sec(x)?

First of all, multiply secx by (secx+tanx)/(secx+tanx). Use the substitution u=secx+tanx, so that du=(secxtanx+sec 2 x) dx and then substitute both terms. Calculate the integral of the du/u arriving at ln|u|...
CK
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A child is standing on a walkway that is moving at 2 metres per second and decides to turn around and walk back to the start at 2 metres per second. Explain why the child cannot reach the start of the walkway at this speed.

Assuming that the walkway is moving in a positive direction, the child is walking in the opposite direction to it and is therefore walking in the negative direction. Both the child and the walkway have veloc...
MS
Answered by Merry S. • Physics tutor
2359 Views

Find the maximum point of the curve from its given equation: [...]

Firstly you would have to differentiate the equation to find the expression that describes the rate of change of the parameters relative to each other using the standard differentiation method. This involves...
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Answered by Merry S. • Maths tutor
4038 Views

Why do we use the dative case?

The dative is used to show that a noun is an indirect object in the sentence. This means it is the person or thing receiving the action. For example: 'Der Mann gibt dem Hund einen Knochen'. So here, the man ...
MR
Answered by Molly R. • German tutor
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