What is the term for the point in a planet's orbit where it is closest to the Sun?

In the context of electricity, what does DC stand for?

Which law of thermodynamics states that energy cannot be created or destroyed, only converted from one form to another?

What is the chemical symbol for silver nitrate?

What does the term "Ohm's Law" describe?

Which of the following is a process of coastal erosion where waves cut into rock and form a notch along the shoreline?

What type of boundary is characterized by the sliding or rubbing motion between two tectonic plates?

What is the SI unit of magnetic flux?

What is the term for the process by which water returns to the Earth's surface from the atmosphere in the form of rain, snow, sleet, or hail?

What is the name for the point in a system where the entire mass can be considered to be concentrated for purposes of calculations?