Astudent hears in chemistry class that a certain object is made of a pure substance. what can the student conclude about the object based on this information?

The object is made up either elements or a compound.

Explanation:

A pure substance is defined as the substance which is formed by same or different type of atoms which are chemically combined in a fixed ratio by mass.

Elements and compounds are considered as pure substances.

Elements are formed by the combination of similar type of atoms and compounds are formed by the combination of different type of atoms.

We are given:

An object is made of a pure substance.

Hence, the object is made up either elements or a compound.

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

the answers would be

the first one and the second one