Sacrificial protection takes place when a magnesium block is attached to the steel on oil rigs. Which metal is 'sacrificed' and
which is protected? Explain your answer.

Explained below.

Explanation:

In oil rigs, Sacrificial protection is the protection of the steel against corrosion by using magnesium block which is a more reactive metal. This means that steel which is to be protected from corrosion will be the cathode while magnesium block preventing it from corrosion will be the anode and as such the block will be the one to corrode instead.

The mechanism behind this sacrificial protection is that the steel pipe on the rig will be connected to the magnesium block through copper wires and then the magnesium block will donate its electrons to the steel thereby preventing it from rusting. Thus is a reversible reaction and as such, after the steel Iron undergoes oxidization by receiving electrons from the magnesium block, it will be immediately be reduced to iron as depicted in the equation below.

Mg⇌Mg^(2+) + 2e-

Fe^(2+) + 2e-⇌Fe

state the principle of separating two immiscible liquids by separating funnel. describe an activity with diagram to separate a mixture of water and kerosene oil. answer: immiscible layers separate out in layers depending on their densities in separating funne

answer is: nuclear fusion produces elements that are heavier than helium.

nuclei combine to form a heavier nucleus, releasing energy.  

for example, fusion of hydrogen atoms at the sun.  

this fusion nuclear reaction is in the inner core of the sun and hydrogen (atomic number 1) is conveted into helium (atomic number 2).  

the inner core is the central region of the sun and all solar energy is produced in the core by nuclear fusion.