On the periodic table, calcium and bromine are located in period 4. What is one difference between the two elements?

A. Calcium atoms are more reactive than bromine atoms.

B. Bromine and calcium atoms will each combine with the same elements to form compounds.

C. Calcium atoms combine more easily with other atoms in Group 2.

D. Bromine atoms have more electrons in their outer shell than calcium atoms.

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.

How many mmols of tris-hcl are there in 100 ml of a 100 mm tris-hcl buffer solution at ph 8.1? note that the 100 mm refers to the sum of tris and tris-hcl concentrations?

In a reaction equation, where are the products located? a.) above the arrow b.) to the right of the arrow c.) to the left of the arrow d.) below the arrow