Explanation:
One of the laws of gases states that, for a fixed amount of gas held at a constant temperature, the volume of a gas is inversely proportional to its pressure.

Explanation:
The s orbital has a spherical shape. In terms of energy, s has the lowest, followed by p and d orbital. Thus, Choices A, B, and D are all incorrect

Explanation:
The molar mass of sodium phosphate is 163.94 g mol−1. Divide the mass (20.5 g) of sodium phosphate by the molar mass to calculate the number of moles of the compound. The rest of the choices are incorrect.

Explanation:
The student must first understand that each component of the mixture will result in one spot on the paper chromatogram. If the recrystallization was successful, then the purified dye should only have one dot.
Therefore, answer choice B is incorrect since the sample contains more than one component after recrystallization.
Answer choice C indicates that the dye is no longer in the sample, and answer choice D indicates the contaminant was not successfully separated from the dye. So the paper chromatogram is unable to identify any impurities that are still present.
In answer choice A, before recrystallization, shows two components (the dye and contaminant), and after, there is only one component showing successful recrystallization.
This question is categorized as medium since the student must understand the premise and purpose of paper chromatography and apply it to experimental results

Explanation:
Successive ionization energies are larger, as electrons are removed, there is less electron-electron repulsion, so the remaining electrons are pulled closer to the nucleus, and more energy is required to remove them.

Explanation:

Isotopes are atoms of the same element with different numbers of neutrons that differ only in terms of their physical properties.

Explanation:
For p, $l$ is equal to 1. The number of electrons in a given subshell can be calculated using the formula: $6$ electrons.

The p subshell holds 3 orbitals. Each orbital can fit 2 electrons. Therefore, p subshell holds 6 electrons.

Explanation:
Second ionization energy is the energy required to remove one mole of electrons from one mole of singly positive gaseous ions.

Explanation:
Explanation: Selenium's electron configuration is 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^4. The three $2p$ and three $3p$ orbitals are fully occupied, along with one 4p orbital.

Explanation:
The number of arrows denotes the number of electrons the atom has. The orbital diagram shown here has 8 arrows which tells you that there are 8 electrons.
Choice A is not correct because C has only 6 electrons.
Choice D is also not correct because F has 9 electrons.
Choice C is incorrect as N has 7 electrons.
Among the choices, oxygen in its neutral form has 8 electrons. Hence, choice B is the correct answer.

Explanation:
The student must first recall that the component with the greatest affinity for the mobile phase will travel the furthest in paper chromatography. In this case, spot #2 is the furthest from the starting line, so it has the greatest affinity for the mobile phase.
In paper chromatography, the mobile phase is always the solvent (water, in this case), while the stationary phase is the paper.
This question is categorized as easy because the student must only recall basic definitions and concepts for paper chromatography.

Explanation:
Statement I is true because emission spectra are produced when photons are released from excited electrons returning to lower energy levels.
Statement II is true because this is Pauli’s Exclusion principle.
Statement III is also true because it is included in Pauli’s Exclusion principle.

Explanation:
The graph of P vs T shows a linear graph (straight line passing through the origin) that rises upward. This graph shows that P is directly proportional to the absolute temperature. As the absolute temperature increases, the pressure of the gas also increases.

Explanation:
Choice A is the correct answer because it satisfies Aufbau's principle and the number of electrons in the electron configuration aligns with the same number of electrons in the orbital diagram.

Explanation:
Choice B is incorrect because electrons are not located in the nucleus. Choice C is incorrect because an orbital diagram is just a representation of electrons in an orbital. Choice D is incorrect because electrons can be found in orbit (a specific energy level around the positively charged nucleus) but the probability is relatively low. Choice A is the correct answer: orbitals are areas/ regions in space where the probability of finding an electron is very high.

Explanation:
Vanadium has an atomic number of 23 therefore statement I is true. It also has a mass number of 51, therefore statement II is also true as nucleons include both protons and neutrons. Statement III is false as the closest noble gas is Ar, not Ne. The correct condensed electron configuration would be [Ar]4s23d^3. Therefore, the correct answer is A.

Explanation:
Second ionization energies are higher than the first as the electrons are being removed from a positive ion resulting in a stronger electrostatic attraction.
First ionization energies do increase across a period due to increasing nuclear charge.
First ionization energies also decrease down a group due to increased shielding (number of shells).

Explanation:
The shortest wavelength corresponds to a higher frequency and therefore a higher energy transition. The 5p to $1s$ represents the largest energy drop and therefore would produce the shortest wavelength.

Explanation:
At high pressures and very low temperatures, the inter-particle forces strengthen, spaces between particles decrease causing the deviation from ideal gas behaviour PV/nRT > 1.

Explanation:
The atomic number of sodium is 11. The atom loses one electron to become a stable ion with a charge of 1+ (10 electrons).
Choice A is incorrect because it shows the electron configuration of a sodium atom, not sodium ion. Choice B is incorrect because it shows an increase instead of a decrease by 1 electron.
Choice D is incorrect because of 2s^1.
Choice C is the correct answer. Ne has an atomic number 10. In a neutral atom, the number of electrons is equal to the number of protons. Therefore, Ne has 10 electrons in its atom. Sodium ion has 10 electrons too.

Explanation:

Electrons have negligible mass.

Explanation:
Add 273 to the temperature in Celsius to convert it to Kelvin. −185∘C+273 = 88K. The rest of the choices are incorrect.