Chemistry For The Cst

1. The model of ideal gases shown above is useful because it?

Shows a linear relation between gas pressure and volume.

Accurately approximates the properties of most gas molecules.

Predicts the behavior of other phases of matter.

Gives precise explanations for nonideal gas behavior.

The model of ideal gases is a theoretical model that assumes gas particles as point masses with no volume and no intermolecular forces. It is useful because it provides a good approximation of the behavior of most gas molecules, despite not accounting for all possible scenarios such as nonideal gas behavior, behavior of other phases of matter, or a linear relation between gas pressure and volume.

Explanation

The model of ideal gases is a theoretical model that assumes gas particles as point masses with no volume and no intermolecular forces. It is useful because it provides a good approximation of the behavior of most gas molecules, despite not accounting for all possible scenarios such as nonideal gas behavior, behavior of other phases of matter, or a linear relation between gas pressure and volume.

2. When a metal is heated in a flame, the flame has a distinctive color. This information was eventually extended to the study of stars because?

A red shift in star color indicates stars are moving away.

Star color indicates absolute distance.

The color spectra of stars indicate which elements are prese

It allows the observer to determine the size of stars.

The color spectra of stars indicate which elements are present because just like in the case of heating metals in a flame, different elements emit distinct colors when heated. By studying the color spectra of stars, astronomers can determine the composition of elements in a star.

Explanation

The color spectra of stars indicate which elements are present because just like in the case of heating metals in a flame, different elements emit distinct colors when heated. By studying the color spectra of stars, astronomers can determine the composition of elements in a star.

3. Why is cobalt (Co) placed before nickel (Ni) on the periodic table of the elements even though it has a higher average atomic mass than nickel?

Nickel has one more proton.

Cobalt was discovered first.

Cobalt has a lower density.

Nickel has fewer electrons.

In the periodic table, elements are arranged based on their atomic number (number of protons). Since nickel has one more proton than cobalt, it is placed before cobalt on the periodic table regardless of the difference in average atomic mass.

Explanation

In the periodic table, elements are arranged based on their atomic number (number of protons). Since nickel has one more proton than cobalt, it is placed before cobalt on the periodic table regardless of the difference in average atomic mass.

4. Generally, how do atomic masses vary throughout the periodic table of the elements?

They increase from left to right and top to bottom.

They increase from right to left and bottom to top.

They increase from right to left and top to bottom.

They increase from left to right and bottom to top.

The correct trend for atomic masses in the periodic table is that they increase from left to right and top to bottom. This is due to the arrangement of elements based on their atomic number and the filling of electron shells.

Explanation

The correct trend for atomic masses in the periodic table is that they increase from left to right and top to bottom. This is due to the arrangement of elements based on their atomic number and the filling of electron shells.

5. Which of the following atoms has the largest atomic radius?

Chlorine (Cl)

Barium (Ba)

Iodine (I)

Magnesium (Mg]

The correct answer is barium (Ba) as it is located in the same period as the other elements but has more electron shells, leading to a larger atomic radius.

Explanation

The correct answer is barium (Ba) as it is located in the same period as the other elements but has more electron shells, leading to a larger atomic radius.