The answer is around 4.12x10^23 molecules
Well you know that you have to balance out the equation to 0. So if I is -1 and Ca is +2 you know that I had to equal to -2. So you can do that by having two of them. So Ca=+2 and I2=-2 so CaI2 would equal 0 meaning that would be the correct answer. Hope that I explained that correct :)
Answer:
Elaina's scientific investigation is missing controlled variables.
Explanation:
A good scientific investigation should vary only the factor that is studied (the speed of the music. All other factors should be kept constant.
She hasn’t controlled for <em>volume</em>. The volume of the music may affect the rate at which the listener’s heart rate will increase. She should have measured each person’s pulse after the same period of listening.
She hasn’t controlled for <em>age</em>. A grandmother may respond to loud music differently from a teenager. All her subjects should be about the same age.
She hasn’t controlled for <em>wakefulness</em>. A person may respond to music differently when awake than when asleep.
