Students in a science class observed that when a strip of Magnesium (Mg) metal was placed in a test tube containing Hydrobromic acid (HBr), the Magnesium began to bubble as hydrogen gas and Magnesium Bromide are formed. Which of the following choices show both the correctly balanced equation and identify the type of reaction? A.
Mg+2HBr →H2+MgBr2 (synthesis)

B.
2Mg+HBr →H2+2MgBr2 (decomposition)

C.
Mg+2HBr →H2+MgBr2 (single replacement)

D.
Mg+2HBr →2H2+MgBr2 (double replacement)

Pls help, I'll mark brainiest, I really need a good grade, so pls answer correctly

Which statement correctly describes the relationship between frequency and wavelength?

The act of moving from one place to another. a. locomotor b. aerobic c. stationary d. static

Aball is thrown from the top of a building with an initial velocity of 21.9 m/s straight upward, at an initial height of 51.6 m above the ground. the ball just misses the edge of the roof on its way down, as shown in the figure. (a) determine the time needed for the ball to reach its maximum height. (b) determine the maximum height. (c) determine the time needed for the ball to return to the height from which it was thrown, and the velocity of the ball at that instant. (d) determine the time needed for the ball to reach the ground. (e) determine the velocity and position of the ball at t = 5.35 s.