Answer: TWO.
At least two groups: treatment group and control group.
The treatment group is that is exposed to the different levels of the independent variable ( a medication for example), while the control group is not treated, so the researchers can compare the effect of the medication.
Answer:
C
Explanation:
electronic waves transmits energy but mechanical waves require a medium in order to transport their energy from bgg one place to another.
Answer:
The atomic number equals the charge on the nucleus. It therefore also equals the number of protons in the nucleus and also equals numerically the number of electrons in the neutral atom. i think so, hope this helps you
Explanation:
A total lunar eclipse takes place when the Earth comes between the Sun and the Moon and covers the Moon with its shadow. When this happens, the Moon can turn red, earning it the nickname of Blood Moon.
