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Why does an absorption spectrum (of eg Helium) show dark lines?

Ignoring the dark lines, we have a continuous colour (visible light) spectrum. The dark lines represent where the photon of a particular wavelength is missing, hence we cant see it. This occurs when the ligh...
JB
Answered by James B. Physics tutor
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Explain the characteristics of enzymes and the lock and key theory of enzyme action. Explain the role of enzymes in catabolic and anabolic reactions.

1) enzymes are biological catalysts that will speed up reactions by reducing activation energy for the reaction. 2) Lock and key theory concerns how the enzyme (lock) only forms a reactive complex with a spe...
JB
Answered by James B. Biology tutor
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Discuss the nature nurture debate in Psychology?

Nature : behaviour is heredity. Nurture : behaviour is caused by the environment, experience and learning. Interactionist approach: the belief that both nature and nurture are essential to any behaviour. A k...
KV
Answered by Katie V. Psychology tutor
19290 Views

Solve this quadractic equation: x^2 - 8x + 15 = 0

To solve x 2 - 8x + 15 = 0 we could try to use the Product, Sum, Numbers method (PSN). The PSN method tells us that our numbers must multply to make the product of the first and last term, in this case 15. I...
TS
Answered by Toby S. Maths tutor
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Use integration by parts to find the integral of xsinx, with respect to x

The integration by parts rule looks like this: ∫ u * v' dx = u * v - ∫ ( v * u' ) dx Hence in this example, we want to make our u = x and v' = sinx So we now need to work out what u' and v are: u' = 1 which ...
TS
Answered by Toby S. Maths tutor
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