Answer:
1) A chemical reaction is shown.
SnO2 + H2 → Sn + H2O
What is true about this chemical reaction?
B.
It is unbalanced because the mass of the reactants (number of atoms) is greater than the mass of the products (number of atoms).
2) Read the information about an experiment.
Jadon plans on carrying out an experiment involving the burning of steel wool to illustrate the conservation of mass. Steel wool is made of iron. When it is burned it combines with oxygen to form iron(III) oxide.
Which step in his experiment is the most important if he wants his experiment to correctly demonstrate the conservation of mass?
A.
The steel wool should be burned inside of a sealed jar or other closed system.
Explanation:
The explanation to number 1 is that I selected it in my test and got it.
The explanation the number 2 is from the link below:
https://quizizz.com/admin/quiz/5dee60258f1145001bc02ed5/physical-science-2nd-9-weeks-practice-test-2020
Answer:
The letters of DNA pair up because they form hydrogen bonds: each contains hydrogen atoms, which are attracted to nitrogen or oxygen atoms in their partner
Explanation:
C)fossil aging and no i did not use google i knew this from 7th grade
