What do we mean when we say a chemical reaction is balanced? (several choices can be correct.)
there is an equal number of solids, liquids, and gases on both sides of the reaction arrow.
there is an equal number of products on the right side of the equation as there are reactants on the left side of the
arrow.
the total number of each atom is the same on both sides of the reaction arrow.
the net charge on both sides of the reaction arrow is the same.

Look at the spectrums of a star moving towards earth and a motionless star. which of these is a correct inference that can be draw from the observation of the two spectrums? (2 points) the spectrum of a motionless star is difficult to be viewed separately using oridinary telescopes. the spectrum of a motionless star is identical to the spectrum of a star which moves towards earth. the spectrum of a star shifts towards the red region when the star moves towards earth. the spectrum of a star shifts towards the blue region when the star moves towards earth.

Which rate indicates the number of children that would be born per woman if she were to live to the end of her child bearing years

Describe at least two advantages and two disadvantages of using hydropower as a source of energy.