Which substance is mainly composed of a subgroup of lipids? A. beef
B. butter
C. soybean
D. flour

B. butter

Explanation:

Butter is the substance which is mainly composed of the subgroup of lipids.

k

explanation:

k

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