$$\text{Number of neutrons} = \text{Mass number} - \text{Atomic number}$$

Question 1

Which of the following statements best describes a metalloid, based on its position in the periodic table and its properties?

Accepted Answer

A metalloid exhibits properties of both metals and nonmetals and is located along the zigzag line on the periodic table.

Question 2

Which element is represented by the chemical symbol 'Au', and what is the origin of this symbol?

Accepted Answer

Gold; from the Latin word 'aurum'

Question 3

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

Accepted Answer

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

Question 4

Which of the following best explains why atoms are electrically neutral?

Accepted Answer

Atoms have equal numbers of protons and electrons.

Question 5

A sample contains two isotopes of carbon: $$^{12}_{6}\mathrm{C}$$ and $$^{14}_{6}\mathrm{C}. $$Which statement is true about these isotopes?

Accepted Answer

They have the same number of protons but different numbers of neutrons.

Question 6

Which group and period does the element with the symbol 'Br' belong to?

Accepted Answer

Group 7A (17), Period 4

Question 7

Which of the following elements is a major element in the human body?

Accepted Answer

Oxygen (O)

Question 8

According to Dalton’s atomic theory, which of the following is NOT correct?

Accepted Answer

Atoms can be created or destroyed during a chemical reaction.

Question 9

A neutral atom of magnesium has an atomic number of 12 and a mass number of 24. How many neutrons does it have?

Accepted Answer

$$24 - 12 = 12$$ neutrons

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

Which of the following best describes the difference between a metal and a nonmetal?

Accepted Answer

Metals are good conductors of heat and electricity, while nonmetals are poor conductors.

Question 12

Which of the following is the correct formula for calculating the number of neutrons in an atom?

Accepted Answer

$$	ext{Number of neutrons} = 	ext{Mass number} - 	ext{Atomic number}$$

Question 13

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

Accepted Answer

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

Question 14

Which of the following elements is a metalloid and is commonly used in semiconductors?

Accepted Answer

Silicon (Si)

Question 15

If an atom has 26 protons, 32 neutrons, and 26 electrons, what is its atomic symbol?

Accepted Answer

$$^{58}_{26}\mathrm{Fe}$$

Question 16

Which of the following statements about subatomic particles is correct?

Accepted Answer

Protons and neutrons are found in the nucleus, while electrons are found outside the nucleus.

Question 17

Which of the following elements is classified as a macromineral essential to human health?

Accepted Answer

Calcium (Ca)

Question 18

A student claims that the mass number of an element can be found directly on the periodic table. Is this correct? Why or why not?

Accepted Answer

No, because the periodic table lists the atomic number, not the mass number.

Question 19

Which of the following best describes the charge and mass of a neutron?

Accepted Answer

Charge: $$0$$, Mass: $$1.008$$ amu

Atoms, Elements, and the Periodic Table: Foundations of GOB Chemistry

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