Read the list of elements given below. Be, Mg, Ca, Sr Which of the following about the elements is true? (5 points) All of them are unreactive metalloids.
All of them are hard and dense metals
. Be and Mg are hard and dense metals and Ca and Sr are unreactive metalloids.
Be and Mg are unreactive metalloids and Ca and Sr are hard and dense metals.

A100-watt light bulb radiates energy at a rate of 100 j/s. (the watt, a unit of power or energy over time, is defined as 1 j/s.) if all of the light emitted has a wavelength of 525 nm , how many photons are emitted per second?

Plz mark brainliest 30 points 1) find the momentum of a 12 kg snowball that is rolling with a velocity of 9 m/s. 2) an 8 ball with a mass of .5 kg is sitting at rest. it is hit by the cue ball (1 kg) traveling at 2.5 m/s. if the cue ball is at rest after the collision, how fast is the 8 ball traveling after the collision? 3) two football players are running toward each other. if the offensive player is 75 kg and is running 8 m/s, how fast must the 60 kg defensive player run in order for the two players to hit and stop?

Light waves are as they pass through the