Aluminum (AI) has an atomic number of 13 and an atomic mass of 27. Which of the following correctly shows the electron arrangement for aluminum?
2,8, 3
2,8,1
2,11
2,8,17

There are 6.022 x 10^23 atoms of hg in 1 mole of hg. the number of atoms in 4.5 moles of hg can be found by multiplying 4.5 by 6.022 x 10^23 a. 2.7 x 10^24 b. 27 x 10^23 c. 2.71 x10^24 d. 27.099 x 10^23

The diagram shows the structures of horse and cat forelimbs. what does the diagram suggest about the evolutionary relationship between these two mammals? a. they have homologous structures, indicating a common ancestor. b. they have analogous structures, indicating a common ancestor. c. they have homologous structures, indicating that they do not have a common ancestor. d. they have analogous structures, indicating that they do not have a common ancestor.

Which type of substance ionizes partially and gives off hydrogen ions when dissolved in water? a. strong acid b. strong base c. weak acid d. weak base