Which of the following combinations of elements is most likely to produce covalent bonds?

a. hydrogen & helium

b. sodium & magnesium

c. fluorine & bromine

d. aluminum & bromine

Explain what happens to the pitch of a cell phone ring when the wavelength of a sound wave increases

Cart A, with a mass of 0.4 kg, travels on a horizontal air track at 6 m/s and hits cart B, which has a mass of 0.8 kg and is initially at rest. After the collision, cart A has a velocity of 2 m/s in the opposite direction.

The driver of a car moving with a constant speed applies the breaks, and the car comes to a stop after traveling 3.5 meters. Which force causes the deceleration of the car?

Aleksei's family purchased a new water heater that is a heat pump. After installation, Aleksei noticed that the room containing the new water heater felt cooler than the rest of the house.

A circuit has a 9.0 v power supply and two resistors connected in parallel. one resistor is 10, and the other is 15. what is the current across the 15 resistor?

Materials with a density__water will float in water

A 0.5 kg ball is thrown horizontally towards a wall with a speed of 10 m/s. The initial velocity is chosen to be the positive x - direction for this question.

Does heat rise or fall

Two small, positively charged spheres have a combined charge of 5.23 x 10^-5 C. If each sphere is repelled from the other by an electrostatic force of 1.00 N when the spheres are 2.

A car racer accelerates uniformly to a velocity of 135 m/s over a distance of 412 m. Determine the acceleration of the car.