A deer is running across a meadow at a speed of 15 m/s. Katie is riding in a car that is traveling at 25 m/s in the opposite direction as the deer. To Katie, the deer appears to be moving at a speed of 35 m/s.
Joan is standing still beside the meadow. To Joan, the deer appears to be moving at a speed of 15 ms.
Why do Katie and Joan believe the deer is traveling at different speeds?
A. Joan is not able to see clearly.
B. They are not the same height and weight.
C. They have different frames of reference.
D. Katie's car is going too fast.

D

Explanation:

C they have different frames of reference

Explanation:

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer