Question 1

Which of the following statements best describes an element?

Accepted Answer

An element is a pure substance from which all other things are built and cannot be broken down into simpler substances.

Question 2

Which chemical symbol is correctly paired with its element?

Accepted Answer

Cl for chlorine

Question 3

The element with the symbol 'U' is named after which source?

Accepted Answer

The planet Uranus

Question 4

Which of the following is a property of metals?

Accepted Answer

They are shiny, ductile, and malleable.

Question 5

Which element is a metalloid?

Accepted Answer

Silicon (Si)

Question 6

What is the atomic number of carbon?

Accepted Answer

6

Question 7

If an atom has 20 protons and 20 electrons, what is its net charge?

Accepted Answer

Zero

Question 8

How many neutrons are in an atom of potassium with a mass number of 39 and atomic number of 19?

Accepted Answer

20

Question 9

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

Accepted Answer

$$^{12}\mathrm{C}$$ and $$^{14}\mathrm{C}$$

Question 10

Which element has the highest ionization energy among the following?

Accepted Answer

Bromine (Br)

Question 11

What is the electron arrangement for magnesium (Mg), atomic number 12?

Accepted Answer

$$2, 8, 2$$

Question 12

Which group on the periodic table contains the noble gases?

Accepted Answer

Group 8A (18)

Question 13

How many valence electrons does phosphorus (P) have?

Accepted Answer

5

Question 14

Which of the following energy level changes involves the absorption of energy?

Accepted Answer

An electron moves from $$n=1 to$$ $$n=3$$

Question 15

Which element has the more metallic character: sodium (Na) or silicon (Si)?

Accepted Answer

Sodium (Na)

Question 16

Which of the following is the correct Lewis symbol for magnesium (Mg)?

Accepted Answer

Mg with two dots placed around the symbol

Question 17

Which of the following statements about atomic mass is correct?

Accepted Answer

Atomic mass is the weighted average of all naturally occurring isotopes.

Question 18

Which element is most likely to be a poor conductor of electricity and have a low melting point?

Accepted Answer

Sulfur (S)

Question 19

Which of the following best explains why chlorine's atomic mass is 35.45 amu?

Accepted Answer

It is the average mass of all chlorine atoms, weighted by isotope abundance.

Question 20

Which of the following elements is most likely to be found as a shiny, malleable solid at room temperature?

Accepted Answer

Gold (Au)

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

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