1. What is the function of the circulatory system? * 10 points A. Provide blood with oxygen from the air, & to get rid of carbon dioxide B. Carry oxygen, nutrients, waste, & to fight pathogens C. Secrete hormones to regulate the body and maintain homeostasis D. Produce red blood cells, white blood cells, & platelets

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

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