1. a substance that is changed during a chemical reaction is called
2. matter cannot be created or__
in a chemical reaction.
3.
takes place during the formation of rust.
4. increasing surface area of a reactant
- the speed of the reaction.

This line graph compares the growth of plants that were kept in the sun for different amounts of time.a)  on day 7, the plants kept in the sun for 3 hours were how tall? b)  on day 7, the plants kept in the sun for 6 hours were how tall? c)    on day 10, the plants kept in the sun for 9 hours were how tall? d)  on day 11, the plant that was grown with 1 hour of sunlight was how tall? e)  based on the graph, the plant grows best in what amount of sunlight?

The volume of a single vanadium atom is 9.29×10-24 cm3. what is the volume of a vanadium atom in microliters?

Choose all the answers that apply. fluorine (f) has an atomic number of 9 and an atomic weight of 18.99. fluorine has a. 9 protons b. 10 neutrons c. 18 electrons d. an atomic mass of 19 e. at least one isotope