An element's atomic number is 39. How many protons would an atom of this element have?

Where are the life forms of the biosphere located

How is thermal energy transferred?

an object is dropped from the top of the building through the air friction is present to the ground below how does this kinetic energy just before striking the ground compared to its gravitational potential energy at the top of the building

Estimate how long it would take one person to mow a football field using an ordinary home lawn mower. state your assumptions, such as the mower moves with a 1 km/hr speed, and has a 0.5 m width.

Atomic nuclei are made of protons and neutrons. This fact by itself shows thatthere must be some other type of force in addition to electrical and gravitationalforces. Explain.

When a car turns a corner on a level road, which force provides the necessary centripetal acceleration? 1) gravity 2) normal force 3) air resistance 4) tension 5) friction

Use Newton's universal law of gravitation to explain why gravity is greater on Earth than on Mercury.

What is a magnetic field and how does it interact with magnetic materials?

What is significant about holden sitting on the radiator?

Which of the following occurs in meiosis that does not occur in mitosis 1 fertilization occur 2 body cells are made 3 sex cells are made 4 cell division occurs