Which of these is an element?

-hematite - gold - quartzite - pyrite

A 6.30 kg piece of solid copper metal at an initial temperature T is placed with 2.00 kg of ice that is initially at - 16.0 ∘C. The ice is in an insulated container of negligible mass and no heat is exchanged with the surroundings.

In 1780, in what is now referred to as "Brady's Leap," Captain Sam Brady of the U. S. Continental Army escaped certain death from his enemies by running over the edge of the cliff above Ohio's Cuyahoga River in (Figure 1), which is confined at that

What is warmer during the night: land or sea/ocean?

Anna drew a diagram to compare the strong and weak force. Which labels belong in the areas marked X, Y, and Z?

A kicker punts a football from the very center of the field to the side line 37 yards down field. What is the displacement of the ball? (A football field is 53 yards wide.

Why do two hydrogen atoms bond to form a hydrogen molecule

Suppose the gravitational force between two spheres is 100 N. If the distance between the spheres is halved, what is the new gravitational force between them?

Ilya and Anya each can run at a speed of 8.00 mph and walk at a speed of 3.20 mph. They set off together on a route of length 5.00 miles.

Jill is getting ready to push little Frank in his swing. She pulls Frank back as high as she can and then releases the swing. What is the initial transfer of energy that accelerates the swing when she lets go?

Which phenomenon generates electric current? A black body radiation B ultraviolet catastrophe C emission spectra D photoelectric effect