A single atom of an element has 21 neutrons, 20 electrons, and 20 protons. Which element is it?

Which of the following could you measure with a thermometer

in a lake, there is a patch of lily pads. every day, the patch doubles in size. if it takes 48 days for the patch to cover the entire lake, how long would it take for the patch to cover quarter the lake?

A car traveling at 40 m/s starts to decelerate steadily. It comes to a complete stop in 5 seconds. What is its acceleration? m/s2

A large ship is made out of steel. The density of steel is 7.8 g/cm³. Which explains how this is possible? A. The average density of the ship, which is the combination of steel and air, is lighter than the density of water. B.

The acceleration of the gravity Moon is equal to one-sixth of Earth's gravitational acceleration times. if an astronaut has a mass of 60 kg, what is the mass ande weight of the astronauts on the moon?

What do we call it when an object exerts force on another for a short period of time? * Momentum Work Impulse Friction

Why is flammability a chemical property?

Luke pulls a sled using a force of 65 N for a distance of 25 m across level ground. The rope Luke pulls forms an angle of 25° with the ground. About how much work does Luke do on the sled? 250 J 690 J 1,500 J 1,600 J

Intramolecular and intermolecular forces hold together which of the following? A. atoms within a molecule B. molecules within an object C. charged particles within a salt crystal D. the atoms within compounds E. all of the above

Why is it that a football does not stay in motion at a constant speed when thrown, as the First Law of Motion suggests that it would? 1) Air resistance and acceleration 2) Gravity and mass 3) Distance, mass and gravity 4) Air resistance and gravity