Four students are carrying out different laboratory procedures.
1) piroja is mixing baking soda and vinegar to see if it reacts.
2)jason is heating salt water over a burner until the water evaporates.
3) kali is putting crushed ice and ice cubes on a table to see which melts first. 4)francisco is separating iron filings from sand using a magnet. which experiment relies on convection?

a. piroja’s experiment
b. jason’s experiment
c)kali’s experiment
d)francisco’s experiment

B. Jason's experiment

Option (b) is the correct answer.

Explanation:

Convection is defined as a process in which a fluid is heated an hotter material (less dense) rises at the top whereas cooler material (more dense) sinks at the bottom. This movement of material causes transfer of heat between the materials.

For example, when Jason is heating salt water over a burner until the water evaporates.

Thus, we can conclude that Jason’s experiment relies on convection.

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.