In the reaction HF + Al AlF3 + H2, which two substances would have a coefficient of 2 if the reaction were balanced?

Check all that apply.

A. H2

B. Al

C. AlF3

D. HF

How muck work is done using a 500 watt microwave oven for 5 minutes

What simple machine would move or turn an object? wheel and axle lever screw wedge

The coefficient of linear expansion of steel is 12 * 10-6 k-1. what is the change in length of a 25-m steel bridge span when it undergoes a temperature change of 40 k from winter to summer? a. 1.2 cm b. 1.8 cm c. 1.4 cm d. 2.0 cm e. 1.6 cm

Which of the following is a reversible physical change? a. burning coal b. boiling water c. chopping onions d. bread rising in an oven

The water table is the A. upper boundary of the zone of saturation. B. zone of aeration. C. lower boundary of the zone of saturation. D. aquifer.

How can the time period of a pendulum be decreased or increased

A space probe is sent to the vicinity of the star Capella, which is 42.2 light-years from the earth. (A light-year is the distance light travels in a year.) The probe travels with a speed of 0.9930c.

ngrid kicks a football with an initial velocity of 12 m/s at an angle of 45° relative to the ground. The horizontal component of the initial velocity to the nearest tenth is m/s.

A 60-watt light bulb has a voltage of 120 volts applied across it and a current of 0.5 amperes flows through the bulb. What is the resistance of the light bulb?

In a laboratory experiment, a diffraction grating produces an interference pattern on a screen. If the number of slits in (including the slit spacing) the same, then The fringes stay the same brightness and get closer together.