Question

1. what is a heterogeneous mixture?

a mixture where components are evenly distributed
a mixture where substances are not evenly spread out
a mixture where small particles remain dispersed throughout
a mixture where larger particles settle out over time

1. a chemical formula represents the different

substances in a mixture.
properties of an element.
parts that make up an atom.
elements that make up compounds.
$na^+cl^-$
sodium chloride

Explanation:

For question 19: A heterogeneous mixture is defined as a mixture where the components are not uniformly distributed, so their composition varies across the mixture.
For question 20: A chemical formula uses chemical symbols to show the types and relative numbers of elements that form a compound, as seen in the example NaCl (sodium chloride) which is made of sodium (Na) and chlorine (Cl) elements.

Answer:

1. A mixture where substances are not evenly spread out
2. elements that make up compounds.