Zn (s) + H2 SO4 (aq) → Zn SO4 (aq) + H2 (g) is an example of-
A. change of colour
B. evolution of gas
C. precipitation reaction
D. endothermic reaction

pls anwer fast

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.

7. in the cycle, a virus integrates its dna into the host's dna, and its dna is replicated when the host dna is replicated. a. infectious b. retroviral c. lysogenic d.lytic

Na chemical reaction, activation energy increases the of the reactants. this outcome causes the particles to collide, which results in the of new products.