Acorrosion cell consisting of zinc and nickel is formed. which of the following statement is true? (a) nickel will act as anode (b) zinc will act as anode (c) either metal can act as anode (d) corrosion will not occur

B) Zinc will act as Anode

Explanation:

Standard reduction potential of zinc and nickel are:

Here Zinc undergoes oxidation by loss of electrons, thus act as anode as it has more negative reduction potential.

Nickel undergoes reduction by gain of electrons and thus act as cathode. as it has less negative reduction potential.

Where both are standard reduction potentials.

As the emf is positive, the reaction is spontaneous and reaction will occur.

Thus Zinc will act as anode.

the pull of gravity on the rocket decreases

answer: the correct answer is 1.

explanation: there are various process in which a radioactive nuclei decays:

1) alpha decay: in this process, a heavier nuclei decays into lighter nuclei by releasing alpha particle. the mass number is reduced by 4 units.

2) electron capture: in this decay process, a parent nuclei absorbs an electron and gets converted into a neutron. simply, a proton and an electron combines together to form a neutron. mass number does not change in this process.

3) gamma ray emission: it is a decay process in which an unstable nuclei gives excess energy by a spontaneous electromagnetic process. this decay releases . this process does not change the mass number.

4) positron emission: it is a type of decay process, in which a proton gets converted to neutron and an electron neutrino. this is also known as -decay. in this the mass number remains same.

from the above information, we see that only alpha-decay is producing a change in the mass number of the nucleus.