An object was measured by a worker as 17.400 cm long, however, the manufacturer
specifications list the length of the object
at 17.900 cm. What is the percent error in
the worker's measurement?
a. 2.79% or b. 2.87%

2.79 % error

Explanation:

Percent Error = 100 x [(Actual - Measured) / Actual]

Percent Error = 100 x [(17.900 - 14.700) / 17.900]

Percent Error = 100 x [0.5 / 17.900]

Percent Error = 100 x 0.02793

Percent Error = 2.7932 % or 2.79 %

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.

nacl or sodium chloride is an ionic compound. this is because an ionic compound pertains to a compound that consists of positively and negatively charged ions. in this case, na (sodium) has a tendency to lose one electron when it reacts with with other atoms, so the resulting sodium ion contains 11 protons and 10 electrons, thus making it positively charged (na+), when chlorine reacts, it usually gains one electron to form an ion called chloride, thus making it negatively charged ( since the ions are oppositely charged, they attract.