Ilus A bat bounces a sound wave off a
bird 19.4 m away, and hears the
echo after 0.117 s. What is the
speed of sound in the air?
(Hint: It is not necessarily 343 m/s.)
(Unit = m/s)

If element x has 99 protons how many electrons does it have

What is the mass of the water that is being heated? it requires 2,500 joules to raise a certain amount of water (c = 4.186 jig c) from 20.0°c to 60.0°c. o 159 o 40 g o 63 g o 80 g

Which type of reaction is shown in this energy diagram? energy products activation energy reactants time o a. endothermic, because energy is released to the surroundings o b. exothermic, because energy is absorbed from the surroundings o c. exothermic, because energy is released to the surroundings o d. endothermic, because energy is absorbed from the surroundings