Answer:
A population or community research line can be carried out, wherever at a certain point in time, regardless of whether it is a cross-sectional study.
In addition, the people who would be the population to be studied or the object of study might or might not know the cause of the study (blind) while the researcher could be experimentally participatory.
Explanation:
They are prevalence studies, in which the presence of a health condition or state is determined in a well-defined population and in a determined time frame: one day, one week, a particular moment in life, even if it does not temporarily coincide in all the subjects (for example, the blood pressure figures at the time of entering the school or at the beginning of the holidays, the prevalence of diabetes in hospitalized patients on a given day, etc.).
They are like "photographs" of a state of affairs at a given moment. The simultaneous determination of what is understood by exposure and event does not allow defining causality.
Explanation:
In a galvanic cell, the cathode is positively charged and the anode is negatively charged.
The cathode attracts electron while the anode donates or releases electrons.
Electrons received - Cathode
Electrons donated - Anode
The energy released from 1 gram of uranium is more than 1 million times greater than the energy released from 3 grams of coal is True.
<u>Explanation:</u>
Nuclear Fission is the process in which splitting of a nucleus takes place that releases free neutrons and lighter nuclei. The fission of heavy elements like "Uranium is highly exothermic" and releases "200 million eV" compared to the energy that is released by burning coal which gives a few eV.
In the given example, it is obvious that the energy released from 1 gram of uranium is more than that of the energy released from 3 grams of coal because the amount of energy released during nuclear fission is millions of times more efficient per mass than that of coal considering only 
part of the original nuclei is converted to energy.
1.6456 x 10^3 (ten to the third power)
