Question 1

Which of the following statements best explains why chemistry is considered central to many scientific disciplines, as shown in the course introduction?

Accepted Answer

Chemistry routinely analyzes and creates entirely new forms of matter, impacting fields from medicine to engineering.

Question 2

Which subatomic particle is responsible for the chemical identity (atomic number) of an element?

Accepted Answer

Proton

Question 3

A neutral atom of carbon-14 ($$^{14}C) $$contains how many protons, neutrons, and electrons?

Accepted Answer

6 protons, 8 neutrons, 6 electrons

Question 4

Which of the following best describes an isotope?

Accepted Answer

Atoms of the same element with different numbers of neutrons

Question 5

Which type of chemical bond involves the sharing of valence electrons between two atoms?

Accepted Answer

Covalent bond

Question 6

A sample contains $$3.011 	imes 10$$^{23}$$ atoms of magnesium (Mg$). What is the mass of this sample? (Molar mass of Mg = 24.3$$\ g\ $$mol^{-1}$$, Avogadro's number $$= 6.022 	imes 10$$^{23}$$\ $$mol^{-1}$$)

Accepted Answer

$$12.15\ g$$

Question 7

Which of the following is a real-life example of an ionic compound used in medicine, as discussed in the lecture?

Accepted Answer

Iron(II) sulfate ($$FeSO_4) as an $$iron supplement

Question 8

Which of the following statements about the mass of subatomic particles is correct?

Accepted Answer

The mass of a neutron is almost equal to that of a proton.

Question 9

Photochromic lenses darken in sunlight due to a chemical reaction involving which of the following?

Accepted Answer

Silver ions ($$Ag^+) $$and chloride ions ($$Cl^-) $$forming silver atoms ($$Ag) $$and chlorine atoms ($$Cl)$$

Question 10

Which of the following best describes a cation?

Accepted Answer

An atom that has lost electrons and is positively charged

Question 11

Which of the following is the correct formula for calculating the number of moles ($$n) $$from a given mass ($$m) $$and molar mass ($$M$$)?

Accepted Answer

$$n = \frac{m}{M}$$

Question 12

Which of the following statements about plastics such as polycarbonate is correct, based on the lecture?

Accepted Answer

Polycarbonate is a giant molecule made from bisphenol A and is lightweight yet strong.

Question 13

Which of the following best explains why the mass of an atom is concentrated in its nucleus?

Accepted Answer

The nucleus contains protons and neutrons, which are much more massive than electrons.

Question 14

Which of the following is a correct real-life application of covalent compounds discussed in the lecture?

Accepted Answer

Water ($$H_2O) $$molecules forming hydrogen bonds in ice

Question 15

Which of the following best describes the process of photosynthesis as a source of renewable energy?

Accepted Answer

Conversion of carbon dioxide and water into glucose and oxygen using sunlight

Question 16

A sample of a compound contains 12 g of carbon-12. How many atoms of carbon-12 are present in the sample? (Avogadro's number $$= 6.022 	imes 10$$^{23}$$\ $$mol^{-1}$$)

Accepted Answer

$$6.022 	imes 10$$^{23}$$ atoms

Question 17

Which of the following is NOT a major type of chemical bond discussed in the lecture?

Accepted Answer

Hydrogen bond

Question 18

Which of the following best explains why isotopes of the same element have nearly identical chemical properties?

Accepted Answer

They have the same number of protons and electrons, which determine chemical behavior.

Question 19

Which of the following is a correct example of a metallic bond?

Accepted Answer

Delocalized valence electrons in a copper wire

Question 20

Which of the following best describes the role of iron(II) ion ($$Fe^{2+}) in $$hemoglobin?

Accepted Answer

It binds oxygen molecules for transport in the blood.

CHEM1300 Principles of General Chemistry: Course Introduction and Atomic Structure

Guida di studio - Domande di pratica

Study guide - Flashcard