The answer would be C. in an ellipse
Hope this answer helps!
Answer : Average atomic weight of copper atoms will be
63.62 u.
Explanation : For calculating average atomic weight for any given atom we use this formula,
m = Σ

X % abundance
where, m - avg atomic mass of isotope.
and

- mass of isotope
on solving we get,
m = [63 u X (69/100)] + [65 u X (31/100)] = 63.62 u.
Answer: 16.7 gallon
Explanation:
Given: The car can drive 30.3 miles when 1 gallon of gasoline is used.
Distance covered = 506.3 miles
Thus for 30.3 miles, the amount of gasoline used= 1 gallon
For 506.3 miles, the amount of gasoline used=
Thus the amount of gasoline used is 16.7 gallons.
Answer:
Iron and vermiculite.
Explanation:
Iron and vermiculite are the solid substances used to make a hand warmer. Hand warmers contains iron, water, activated carbon, vermiculite, cellulose, and salt. The high melting, boiling points, hard and brittle are the characteristics of an ionic solid used in hand warmer. Iron is the ionic solid which is used in the hand warmer. Once iron exposed to air, the iron oxidizes and releases heat in the process.