What do astronomers use to calculate the age of the universe? check all that apply. dark energy the age of rocks on earth the age of the oldest stars patterns of background radiation how fast distant galaxies are moving away from us

Liv sheldon given the balanced equation for an organic reaction: c2h2 + 2cl2 → c2h2cl4 this reaction is best classified as *

Acalorimeter is to be calibrated: 51.203 g of water at 55.2 degree c is added to a calorimeter containing 49.783 g of water at 23.5c. after stirring and waiting for the system to equilibrate, the final temperature reached is 37.6 degree c. specific heat capacity of water (s = 4.18 j/g∙degree c). calculate the calorimeter constant. (smδt)warm water = -[(smδt)cold water + (calorimeterδtcold water)]

How many moles are contained in 5.6 l of h2 at stp