Choose the statement that is a misconception about a system in chemical equilibrium.

The rate of the forward reaction is equal to the rate of the backward reaction.

The concentrations of the products and reactants don't change.

There are equal parts reactants and products.

Reactions continue to happen in both directions.

There are equal parts reactants and products.

Explanation:

When a system is in a chemical equilibrium, the rate at which the forward reaction occur is the same as the rate at which the reverse reaction occurs. This system is said to undergo a reversible reaction. The concentration of the reactants and products do not change, i.e are constant.

In a chemical equilibrium, the reaction continues in both directions but at the same rate.

Therefore the statement that is a misconception about a system in chemical equilibrium is 'There are equal parts reactants and products'.

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.