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A heater uses energy from a laptop computer to keep a mug of coffee hot. Energy is transferred to the coffee at the bottom of the mug. Explain how a convection current is set up in the coffee.

The molecules at the bottom of the mug gain energy and spread out as a result. This means that these molecules are less dense than the ones above them so they rise upwards. As they do so, they lose energy...

Answered by Evan H. • Physics tutor

4319 Views

The mercury atoms in a fluorescent tube are excited and then emit photons in the ultraviolet region of the electromagnetic spectrum. Explain (i) how the mercury atoms become excited and (ii) how the excited atoms emit photons.

(i) As they pass through the fluorescent tube, they collide with the mercury atoms within it and this collision transfers energy to the atom. This energy transfer allows the atom's orbiti...

Answered by Evan H. • Physics tutor

26120 Views

Discuss the criminal liability of Mike

In this situation Mike would be charged with Murder.

Murder is a common law offence. It was defined by Sir Edward Coke as the unlawful killing of a living human being, under the queen’s peace, with...

Answered by Gurjant B. • Law tutor

9409 Views

How would one multiply out brackets?

If asked to multiply out a set of brackets, one must remember to multiply each term in a set of brackets by every term in the other set of brackets. For example, (x+2)(x-4) = x²+2x-4x-8 = x

Answered by Alden R. • Maths tutor

4017 Views

Describe and explain the electrical conductivity of lithium oxide, Li2O, and lithium in their solid and molten states.

Lithium conducts electricity in its solid and molten states. Lithium exhibits metallic bonding and as such its valence electrons are delocalised in the liquid and solid state allowing electricty to be con...

Answered by Charlie F. • Chemistry tutor

32611 Views