Question 1

Which of the following statements best describes a metalloid?

Accepted Answer

A metalloid is an element that exhibits properties of both metals and nonmetals and is often used as a semiconductor.

Question 2

Which element is located in Group 2A (2), Period 3 of the periodic table?

Accepted Answer

Magnesium

Question 3

An atom has 17 protons, 20 neutrons, and 17 electrons. What is its atomic symbol?

Accepted Answer

$$^{37}_{17}\mathrm{Cl}$$

Question 4

Which of the following is NOT a characteristic of metals?

Accepted Answer

They are usually gases at room temperature.

Question 5

According to Dalton’s atomic theory, which statement is correct?

Accepted Answer

Atoms of different elements combine to form compounds.

Question 6

A neutral atom of aluminum has an atomic number of 13. How many electrons does it have?

Accepted Answer

13

Question 7

Which of the following pairs are isotopes of the same element?

Accepted Answer

$$^{12}_{6}X$$ and $$^{14}_{6}X$$

Question 8

Which element is a major element in the human body and is also a nonmetal?

Accepted Answer

Oxygen

Question 9

What is the mass number of an atom with 26 protons and 32 neutrons?

Accepted Answer

$$58$$

Question 10

Which experiment led to the discovery that the atom has a small, dense, positively charged nucleus?

Accepted Answer

Rutherford’s gold foil experiment

Question 11

A sample contains only atoms with 8 protons, 8 neutrons, and 8 electrons. What is the atomic symbol for this isotope?

Accepted Answer

$$^{16}_{8}\mathrm{O}$$

Question 12

Which of the following elements is a metalloid?

Accepted Answer

Silicon

Question 13

Which of the following statements about isotopes is correct?

Accepted Answer

Isotopes of an element have the same number of protons but different numbers of neutrons.

Question 14

Which element is found in Group 7A (17), Period 4 of the periodic table?

Accepted Answer

Bromine

Question 15

A neutral atom has 47 protons, 60 neutrons, and 47 electrons. What is its atomic symbol?

Accepted Answer

$$^{107}_{47}\mathrm{Ag}$$

Question 16

Which of the following best explains why electrons are not included in the mass number of an atom?

Accepted Answer

Electrons have a much smaller mass compared to protons and neutrons, so their contribution is negligible.

Question 17

Which of the following elements is a trace element (micromineral) essential to human health?

Accepted Answer

Zinc

Question 18

If an atom has an atomic number of 15 and a mass number of 31, how many neutrons does it have?

Accepted Answer

$$16$$

Question 19

Which of the following best describes the arrangement of electrons in an atom according to the modern atomic model?

Accepted Answer

Electrons occupy a large, empty space around the nucleus.

Question 20

Which of the following elements is a nonmetal and is essential for the structure of DNA and RNA in the human body?

Accepted Answer

Phosphorus

Atoms and Elements: Structure, Properties, and the Periodic Table

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