Define valence electrons and identify the number of valence electrons in an element using periodic table.

How does the matter and energy in a system naturally change over time? A. It increases in energy. B. It becomes more spread out. C. It becomes more efficient. D. It decreases in entropy.

Why does the resistance of thermistors made from semiconductors decrease with temperature, while the resistance of metals increases?

What is the maximum and minimum resultant possible from a 20-N force and 4-N force?

A car of mass 1 000 kg moves with a speed of 50 m/s on a circular track of radius 100 m. What is the magnitude of its angular momentum (in kg⋅m2/s) relative to the center of the race track?

Calculate the final temperature when 50 ml of water at 80°c are added to 25 ml of water at 25°c.

A farmer had 15 sheep, and all but 8 died. How many are left?

While playing with her 5 year old cousin, a Physics 135 student pushed him forward on his scooter. She pushes with a force of 50 Newtons for 3.5 seconds. If the boy and the scooter together have a mass of 30 kg, what is their final velocity? a. 2.

3. A 120.0 V generator supplies 3.0 kw of power. How much current ca the generator deliver?

An apple drops from a tree and hits the ground in 1.5s what is its speed just before it hits the ground?

Sound travels slow in cold air. Why does the speed of sound depend on air temperature?