$$\text{Mass Number} = \# \text{Protons} + \# \text{Neutrons}$$

Question 1

Which of the following statements best describes an element as defined in Chapter 2?

Accepted Answer

An element is a pure substance that cannot be broken down into simpler substances by physical or chemical means.

Question 2

Which property is NOT characteristic of metals according to the study materials?

Accepted Answer

Brittle in solid state

Question 3

Which element is found in Group 2A and the fifth period of the periodic table?

Accepted Answer

Strontium (Sr)

Question 4

What is the atomic number and what does it represent?

Accepted Answer

The atomic number is the number of protons in the nucleus of an atom.

Question 5

Which of the following is a metalloid?

Accepted Answer

Tellurium (Te)

Question 6

How many protons and neutrons are present in a neutral Potassium-40 isotope?

Accepted Answer

19 protons and 21 neutrons

Question 7

Which of the following best describes an isotope?

Accepted Answer

Atoms of the same element with different numbers of neutrons

Question 8

What is the formula for calculating the mass number of an isotope?

Accepted Answer

$$	ext{Mass Number} = \# 	ext{Protons} + \# 	ext{Neutrons}$$

Question 9

Which element is a halogen in the fourth period?

Accepted Answer

Bromine (Br)

Question 10

What is the main difference between metals and nonmetals in terms of electrical conductivity?

Accepted Answer

Metals have high electrical conductivity that decreases with temperature, while nonmetals generally have poor electrical conductivity.

Question 11

Which of the following elements is classified as a main group element?

Accepted Answer

Calcium (Ca)

Question 12

If an atom has 8 protons, 8 neutrons, and 8 electrons, what is its atomic number and mass number?

Accepted Answer

Atomic number: 8, Mass number: 16

Question 13

Which statement about valence electrons is correct?

Accepted Answer

Valence electrons determine the chemical properties of an atom.

Question 14

Which of the following is the correct electron dot symbol for sulfur (S)?

Accepted Answer

S with 6 dots around it

Question 15

Which experiment demonstrated that the atom contains a dense nucleus and is mostly empty space?

Accepted Answer

Rutherford's Gold Foil Experiment

Question 16

Which subatomic particle has a negative charge?

Accepted Answer

Electron

Question 17

What is the charge interplay between protons and electrons?

Accepted Answer

Protons and electrons attract each other.

Question 18

Which of the following is NOT a significant region of the periodic table?

Accepted Answer

Noble Gases as a separate block

Question 19

If an atom is electrically neutral, what must be true about its subatomic particles?

Accepted Answer

The number of protons equals the number of electrons.

Question 20

Which element would you expect to have similar chemical properties to sodium (Na)?

Accepted Answer

Potassium (K)

Atoms and the Periodic Table: Structured Study Notes for GOB Chemistry

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