The answer you are looking for is the second option, "<span>Matter can be divided into two groups: pure substances and mixtures."
A pure substance can describe a pure element or chemically bonded elements. A pure substance cannot be broken down into further substances. An example of these would be Fe (iron) or O2 (oxygen).
A mixture is a structure made from physically combining different non-bonded substances. An example of a mixture is blood.
Both pure substances and mixtures are types of matter.</span>
Answer:they will out live us himans
Explanation:
To develop the chemical formula of a substance or compound in this regard, one only needs to write the chemical symbol for each of the element present and write as subscript to each symbol the number of atoms of that element. For nitrobenzene, as described above, the chemical formula should be,
C₆H₅O₂N
The density of water is a physical property.
You can measure it without changing the water to a different substance.
It is <em>not a physical change</em> because the water does not change to ice or steam.
You can observe a <em>chemical property</em> or a <em>chemical change</em> only if the water <em>changes to a different substance</em>.
