A student was measuring the time it took for an experiment to take place. They found the time to be 40 seconds. However, they had started timing a few seconds after the experiment had started, and the actual time was 43 seconds. What is the percent error?

9.3%

Explanation:

Percent error = (actual value - experimental value / actual value) × 100

In this question, the actual value is 43seconds while the experimental value is 40 seconds

Hence,

%error = (43 - 40 / 43) × 100

%error = (4/43) × 100

%error = 0.093023 × 100

%error = 9.3%

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.