$$\frac{-1.76 \times 10^8$ \text{ C}}{\text{g}}$$

Question 1

Which statement best describes the Law of Conservation of Mass as established by Antoine Lavoisier?

Accepted Answer

In a chemical reaction, matter is neither created nor destroyed.

Question 2

According to Dalton’s Atomic Theory, which of the following is FALSE?

Accepted Answer

Atoms can be converted into energy during chemical reactions.

Question 3

Which experiment led to the discovery that cathode rays are composed of negatively charged particles?

Accepted Answer

J.J. Thomson’s experiment with electric and magnetic fields.

Question 4

What is the charge-to-mass ratio of the electron as measured by J.J. Thomson?

Accepted Answer

$$\frac{-1.76 	imes 10^8$ 	ext{ C}}{	ext{g}}$$

Question 5

Which of the following best illustrates the Law of Multiple Proportions?

Accepted Answer

The ratio of oxygen to carbon in CO and CO$$_2$$ can be expressed as small whole numbers.

Question 6

Which philosopher argued that matter was infinitely divisible, and what was the flaw in his argument?

Accepted Answer

Aristotle; he had no experimental way to prove his theory.

Question 7

A molecule of serotonin has the formula $$C_{10}H$$_{12}$$N_2O$. How many atoms are present in one molecule?

Accepted Answer

25

Question 8

Which of the following is a correct statement about electric charge in atoms?

Accepted Answer

To be neutral, the overall charge must be zero or equal numbers of positive and negative charges.

Question 9

Which real-world application is directly related to the concept of molecules and chemical bonds?

Accepted Answer

The action of SSRIs (like Prozac) increasing serotonin levels in the brain.

Question 10

If a magnesium ion is represented as $$Mg^{2+}$$ and nitrate as $$NO_3$$^-$$, what is the correct formula for magnesium nitrate?

Accepted Answer

$$Mg(NO_3$)_2$$

Question 11

Which of the following best describes the scientific approach established in the late 16th century?

Accepted Answer

Understanding the universe through observation and experiment.

Question 12

What was a major consequence of J.J. Thomson’s cathode ray experiment for atomic theory?

Accepted Answer

It showed that atoms are not unbreakable and contain smaller particles.

Question 13

Which of the following is NOT a fundamental building block of all matter?

Accepted Answer

Energy

Question 14

Which statement best reflects Richard Feynman’s view on scientific theories?

Accepted Answer

If a theory does not agree with experiment, it is wrong.

Question 15

Which of the following is a correct application of the Law of Definite Proportions?

Accepted Answer

All samples of a compound have the same mass ratio of their constituent elements.

Question 16

Which of the following best describes the difference between philosophers and scientists in understanding nature?

Accepted Answer

Philosophers use reasoning and ideal thinking, while scientists rely on observation and experiment.

Question 17

Which of the following is a correct statement about the structure of matter according to Dalton’s Atomic Theory?

Accepted Answer

Atoms of different elements have different masses and properties.

Question 18

Which historical figure placed the sun at the center of the universe, challenging the prevailing view?

Accepted Answer

Nicolaus Copernicus

Question 19

Which of the following is a real-world example of the Law of Conservation of Mass?

Accepted Answer

The total mass of reactants equals the total mass of products in a closed chemical reaction.

Question 20

Which statement about the charge of a hydrogen ion (proton) is correct?

Accepted Answer

Its charge-to-mass ratio is $$+9.58 	imes 10^4$ 	ext{ C/g}.$$

Atoms, Molecules, and Ions: Foundations of Chemistry and Matter

Guida di studio - Domande di pratica