Which of the following is studied at the international space station?

Both physics and biology

Explanation:

In international space station collection of experiments are performs under various circumstances to study Earth orbit. These experiments belongs to astronomy, meteorology, space science, space medicine, physical science, life science, human research.

Astronomy: It is a branch of science that deals with celestial bodies and its performance. Astronomy deals with concept of physics, chemistry and mathematics for explanation of the phenomenon based on celestial bodies. Physics is used for explanation of their position. Chemistry is used for explanation of structure. Mathematics is used in calculation.

Meteorology: It is a branch of science that deals with the atmospheric condition around earth surface. This is generally used ti telecast whether condition around various places on earth. This uses atmospheric physics and atmospheric chemistry.

Physical science: It is a branch of physics that deals natural science and study of non living things. It uses concept related to physics and chemistry.

Space science: It deals with space exploring and its natural phenomenon in science. This uses atmospheric physics, general physics, general chemistry and atmospheric chemistry.

Space medicine: It deals with medicines of astronauts. It uses concept and study under Biology.

Life science: It is a branch of physics that deals with study of life and organism. It uses concept and study under Biology.

Thus, Answer is both physics and biology.

atomic = no of protons.

mass number-atomic number = neutron number