science

Polar molecules are soluble in what substances?

polar

When does covalent bonding take place?

What happens to the electrons of an atom in forming a covalent bond?

What is the correct electron configuration for neon (10Ne)?

An electron in a hydrogen atom moves from the 2nd energy level to the 4th energy level. Based on the Quantum Mechanical Model, what happens to the electron’s energy?

It increases because the electron absorbs energy.

When comparing electrons in the 1s and 3p orbitals, which application of the Quantum Mechanical Model best describes their differences?

The 3p electron has a higher energy and is found farther from the nucleus.

When a magnesium atom reacts with chlorine to form magnesium chloride, what happens to the magnesium atom?

It loses two electrons to form Mg²⁺.

A neutral sulfur atom becomes an ion by gaining two electrons. Which statement correctly applies this process?

Sulfur becomes negatively charged because it gains electrons.

What happens when a sodium atom and a fluorine atom react to form an ionic compound?

Sodium loses one electron and fluorine gains one.

When a sodium atom reacts with a chlorine atom to form sodium chloride, what happens to the sodium atom?

It loses one electron to form Na⁺.

Which of the following compounds is most likely ionic based on its physical properties?

Hard, brittle solid with a high melting point and good electrical conductivity when dissolved in water.

Carbon has four valence electrons in its outer shell. How does this structure affect the type of bonds it can form?

Carbon shares its four valence electrons to form covalent bonds.

An electron transitions from the 3p orbital to the 2s orbital. Analyze what this change reveals about the electron’s energy and probable location.

The electron’s energy decreases, and it becomes more likely to be found closer to the nucleus.

Based on Rutherford’s model of an atom, which sub-atomic particle is present in the nucleus of an atom?

proton and neutron

Which atomic model was proposed by Schrödinger?

quantum mechanical model

What are the orbitals in the fifth principal energy level?

s, p, d, f, and g orbitals

Which principle states that electrons occupy orbitals of lowest energy first before filling in the higher energy levels?

Aufbau Principle

Which of the following sub-atomic particles is negatively charged?

electron

An atom or group of atoms with a charge is known as _.

Ion

What do you think will happen to an atom when it gains or loses electrons? It becomes an/a _.

ion

Who discovered ions?

Faraday

Which type of chemical bonding involves electron sharing?

covalent

Which compound will have a high melting temperature?

sodium chloride (salt)

Which of the following types of bonds will have the highest electrical and thermal conductivity?

metallic bond

If the Quantum Mechanical Model describes electron positions in terms of probability clouds, what can be inferred when the density of the cloud is higher in a certain region?

The probability of finding the electron there is higher.

Analyze what happens to the number of protons and electrons when a neutral oxygen atom becomes an oxide ion (O²⁻).

The number of protons stays the same, but the atom gains two electrons.

Carbon dioxide (CO₂) does not conduct electricity. It exists as a gas at room temperature, while sodium chloride (NaCl) is a solid with a high melting point that conducts electricity when dissolved in water. What conclusion can be drawn about their bonding types based on these properties?

CO₂ is covalent and NaCl is ionic because of their differences in conductivity and melting point.

Is the molecular formula of ethane on the right side correct? Why?

Yes, because the carbon atom is bonded with a hydrogen atom.

How do carbon atoms form many organic compounds?

Forming many bonds with other carbon atoms and other elements.

A scientist argues that the Quantum Mechanical Model cannot predict where an electron will be at any given moment, and therefore, it is unreliable. How should this argument be evaluated?

The scientist is incorrect because the model focuses on predicting probabilities, not exact positions, which is consistent with quantum theory.

A teacher presents two explanations for how a chlorine atom becomes a chloride ion:\nExplanation A: “Chlorine gains one electron to achieve a stable octet.”\nExplanation B: “Chlorine loses one electron to balance its charge.”\nWhich evaluation of these explanations is correct?

Two compounds are tested:\nCompound X: Solid, dissolves in water, and conducts electricity when dissolved.\nCompound Y: Liquid, low melting point, does not conduct electricity.\nWhich evaluation is most accurate?

You are asked to design a new organic compound for use as a liquid fuel. Based on your understanding of organic compound properties, which type of molecule would you create?

A small hydrocarbon molecule with mostly nonpolar covalent bonds.

You are tasked to design a new environmentally friendly cleaning agent using organic compounds. Which type of compound would be most suitable to create, and why?

An alcohol – because it can dissolve both polar and nonpolar substances and can act as a disinfectant.

Which among the following shows that an atom is stable? It has ____

Which of the following is the common use of methane?

fuel

Which of the following describes the boiling point of a compound?

liquid turns to gas

Which of the following statements is NOT TRUE of the atomic model of Bohr?

The energy of the electron in each orbit is not fixed.

For a neutral atom with the electron configuration of 1s² 2s² 2p⁵ 3s¹, which statement is FALSE?

The atom is in the ground state.

If the first and second energy levels of an atom are full, then what would be the total number of electrons in the atom?

10 electrons

What happens to the energy of an electron if it moves from one energy level to another closer to the nucleus?

loses energy

Which of the following describes a neutral atom?

Why is an atom a neutral particle? It is because they have _.

equal number of protons and electrons

How are ions made from neutral atoms? Neutral atoms can be turned into ____

What kind of element has the greatest tendency to attract electrons?

Non-Metals

What kind of element requires high energy to remove its valence electrons?

Non-Metals

In which form of the ionic compound can it conduct electricity easily