Answer:

Explanation:
Quantity of copper measured by a student = 4.6 grams
Original quantity of copper = 4.7 grams
Error in measurement = Original quantity of copper - Quantity of copper measured by a student
grams
To find the percent error, apply the following formula:
Percent error = (Error in measurement / Original quantity of copper) × 100

Answer:
its the fourth one please mark as brainlest
Explanation:
The compound formed is calcium nitrate
The coefficient in a chemical formula represents the amount of each chemical present. The amount of a substance is measured in moles.
The correct reference for this isotope is A. Oxygen-18.