Which is true about chemical reaction changes? a. new substances are always formed b. sometimes new substances are formed c. the change is easily reserved d. there is rarely visible evidence of the change

Plz choose one of the compounds from the table and explain how you know the numbers of atoms in your formula. is it possible for two different compounds to be made from the exact same two elements? why or why not? with a limited number of elements (less than 120 are known), does this mean we also have a small number of compounds or do we have a large number of compounds in this world?

Select the correct answer. which phrase correctly describes temperature? o a. average rotational kinetic energy of the particles in an object o b. average energy of the particles in an object c. average translational kinetic energy of the particles in an object od. all energy possessed by the particles in an object

Adeuteron, 21h, is the nucleus of a hydrogen isotope and consists of one proton and one neutron. the plasma of deuterons in a nuclear fusion reactor must be heated to about 3.02×108 k . what is the rms speed of the deuterons? express your answer using two significant figures.