Chemistry A Quiz 3 Of 3

As the frequency of light decreases, the wavelength becomes longer. This is because wavelength and frequency are inversely proportional to each other according to the wave equation. Additionally, the energy of a photon is directly proportional to its frequency. Therefore, when the frequency decreases, the energy of the photons of light also decreases.

The correct conclusion that resulted from Ernest Rutherford's experiment is that the nucleus is very small and the atom is mostly empty space. This conclusion was drawn based on the observation that most of the alpha particles passed straight through the gold foil without any deflection, indicating that they were passing through the empty space within the atom. However, a small fraction of the alpha particles were deflected at large angles, suggesting the presence of a dense, positively charged nucleus at the center of the atom.

The explanation for the given answer is that the molecules of solid CO2 are much closer together than the molecules of CO2 gas. In a solid state, the molecules are tightly packed and have limited freedom of movement, which makes it difficult to compress the solid CO2. On the other hand, in a gaseous state, the molecules are more spread out and have more space between them, allowing for easier compression. Therefore, solid CO2 is considered to be incompressible compared to CO2 gas.

Disulfur decafluoride is a compound composed of two sulfur atoms and ten fluorine atoms. Therefore, the chemical formula for disulfur decafluoride is S2F10.

The ionization energy refers to the energy required to remove an electron from an atom or ion. The trend in ionization energy across the periodic table generally increases from left to right and decreases from top to bottom. In this case, the statement "The ionization energy of lithium is greater than that of potassium" is accurate because lithium is located to the left of potassium in the periodic table and therefore has a higher ionization energy.

The correct answer is "Sodium is a solid at room temperature and reacts with other elements." This statement describes a chemical property of sodium, specifically its reactivity with other elements. Chemical properties refer to the behavior of a substance when it undergoes a chemical change or reaction. In this case, sodium's ability to react with other elements is a characteristic that distinguishes it from other elements and is therefore an example of a chemical property.

The electron configuration of a potassium atom at ground state is 1s22s22p63s23p64s1. This configuration indicates that there are two electrons in the 1s orbital, two electrons in the 2s orbital, six electrons in the 2p orbital, two electrons in the 3s orbital, six electrons in the 3p orbital, and one electron in the 4s orbital. The movement of electrons between these energy levels is responsible for the observed purple color during a flame test.

In this reaction, zinc is being oxidized because it is losing electrons to form zinc oxide. Oxygen, on the other hand, is being reduced because it is gaining electrons in the formation of zinc oxide. This is a classic example of a redox reaction, where one species is being oxidized and another is being reduced.

The correct answer is 3.01×1023 molecules. This is because 0.500 mole of N2O5 is equal to Avogadro's number (6.02×1023) multiplied by the given amount (0.500). Therefore, the number of molecules in 0.500 mole of N2O5 is 3.01×1023 molecules.

The formula of the ion hydrogen sulfite, which has a charge of -1, is HSO3-1.

The correct answer is Fe(NO3)3(aq) because it balances the chemical equation by providing the correct stoichiometric coefficient for Fe(NO3)3. This ensures that the number of atoms of each element on both sides of the equation is equal, satisfying the law of conservation of mass.

The molecular geometry of methane (CH4) is tetrahedral because it has four bonded atoms and no lone pairs of electrons around the central carbon atom. In a tetrahedral geometry, the bonded atoms are arranged symmetrically around the central atom, forming a three-dimensional shape with bond angles of approximately 109.5 degrees.

The electron configuration for an atom of germanium at ground state is [Ar]4s2 3d10 4p2. This means that germanium has a total of 32 electrons. The [Ar] represents the electron configuration of the noble gas argon, which has 18 electrons. The 4s orbital can hold up to 2 electrons, the 3d orbital can hold up to 10 electrons, and the 4p orbital can hold up to 6 electrons. Therefore, the electron configuration for germanium includes 2 electrons in the 4s orbital, 10 electrons in the 3d orbital, and 2 electrons in the 4p orbital.

In a formula unit of sodium hydrogen carbonate (NaHCO3), there is one sodium atom (Na) present. The molar mass of sodium is 22.99 g/mol. The molar mass of NaHCO3 is 84.01 g/mol. To find the percentage by mass of sodium, we divide the molar mass of sodium by the molar mass of NaHCO3 and multiply by 100. Therefore, the percentage by mass of sodium in NaHCO3 is 27.4%.

Neon and argon are both noble gases, which are gaseous at room temperature and highly unreactive with metals. This is because they have a full outer electron shell, making them stable and less likely to form chemical bonds with other elements. Therefore, the correct answer is "Gaseous at room temperature and mostly unreactive with metals."

The correct answer is 5.606×10^23 atoms. This is because the question is asking for the number of atoms present in a given mass of iridium. To find this, we need to use the concept of molar mass and Avogadro's number. The molar mass of iridium is 192.22 g/mol. We can calculate the number of moles of iridium in 179.0 g by dividing the mass by the molar mass, which gives us 0.930 moles. Then, we can use Avogadro's number (6.022×10^23 atoms/mol) to convert moles to atoms, which gives us 5.606×10^23 atoms.

At STP, one mole of any gas occupies a volume of 22.4 liters. Since there are 2 moles of chlorine (Cl2), the volume would be 2 times 22.4 liters, which equals 44.8 liters.

The atomic radius increases from top to bottom in a group because as you move down a group, the number of energy levels or electron shells increases. This means that the outermost electrons are further away from the nucleus, resulting in a larger atomic radius.