Henry stands outside every night at 9:00 p. m. for one week to observe the stars. Each night, he observes the same group of seven stars. What can you infer from Henry's observations?(2 points) A. That this group of stars is called shooting stars
B. That this group of stars changes every night
C. That this group of stars creates a pattern
D. That this group of stars disappears

C

Explanation:

This group of starts creates a pattern

1. 1 mole of anything contains 6.022x10^23 pieces  

d  

2. a  

3. c, number  

5. 1.24x10^24atoms / 6.022x10^23atoms/mole = 2moles h2 atoms  

6. fe2br3 mass = 2moles x mass fe + 3 moles x mass br  

molar mass = grams / number of moles = g/mole  

to find moles = g / molar mass  

to find mass = g = molar mass / moles

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.