Answer:
The law of conservation of mass states that mass is neither created nor destroyed but the mass of the system must remain constant over time. The total number of atoms in the reactants is equal to the total number of atoms in the product. Therefore, this chemical equation shows that energy is conserved and demonstrates the law of conservation of mass.
The statement that best describes waves is B. Waves cannot propagate without a medium
Answer: C
Explanation:
The impact she has on the environment
For 60.0 g sample, if it remains 60-52.5=7.5 g, it will go through 60->30->15->7.5, 3 half-life. So the time being taken is 269*3=807 years.