Chemical reactions
What are the key indicators that a chemical reaction has occurred.
change in color, energy change (temperature change or light produced), and gas production.
What is the key chemical characteristic that differentiates an acid from a base?
pH levels
What is the electron configuration of Oxygen (O)?
1 s 2 2 s 2 2 p 4
What are the three subatomic particles that make up an atom, and what are their respective charges?
protons, neutrons and electrons.
What are the three primary states of matter, and how are they differentiated based on particle arrangement?
gas are well separated with no regular arrangement. liquid are close together with no regular arrangement. solid are tightly packed, usually in a regular pattern.
How can you identify the reactants and products in a chemical reaction when given a balanced equation?
by their position relative to the chemical reaction arrow.
How does the pH scale measure the acidity or basicity of a solution?
pH is really a measure of the relative amount of free hydrogen and hydroxyl ions in the water.
How many valence electrons does an element with the electron configuration [Ne] 3s2 3p3 have?
5
How does the number of protons in an atom determine its identity as an element (atomic number)?
The number of protons plus the number of neutrons in a nucleus determines an element's “baryon number,” which is nearly equal to the atomic mass of that element.
How do you distinguish between a pure substance (element or compound) and a mixture, and what are the key characteristics of each?
Elements and compounds are pure substances, but mixtures are not.
Explain the concept of "conservation of mass" in relation to chemical reactions, and how it is represented in a balanced equation.
Balanced chemical equations show that mass is conserved in chemical reactions.
Give an example of a common house hold acid and a common household base.
vinegar, toilet bowl cleaners, lemon juice, and soda.
which element has the same electron configuration as a Calcium ion (Ca2+) in its noble gas form?
Argon (Ar).
Explain the concept of electron shells and how they are related to an atom's reactivity.
determining how readily an atom will form bonds with other atoms.
Explain the difference between a homogeneous mixture and a heterogeneous mixture, and provide an example of each.
Heterogonous mixtures are ones in which their constituents do not mix uniformly, while homogenous mixtures are ones in which they mix uniformly.
What are the different types of chemical reactions and how can you distinguish between them?
Balanced chemical equations show that mass is conserved in chemical reactions.
What happens when an acid and a base react with eachother?
Acid and bases react to form salt and water.
Explain the difference between the "s" orbital and the "p" orbital in terms of their shape and how many electrons they can hold.
The s sublevel has only one orbital, so max. 2 electrons can be present. The p sublevel has 3 orbitals, so max. 6 electrons can be present.
What is the difference between an isotope and a regular atom of the same element?
Isotopes are atoms of the same element that have the same number of protons (i.e., atomic number, "Z") but a different number of neutrons.
Can a substance change its state of matter without altering its chemical composition? if so, is this considered a physical or chemical change?
It is still the same, physical changes.
An example of a chemical reaction that occurs in everyday life, and explain the chemical process involved?
rusting, which happens when iron turns a red or brown color due to exposure to air and water.
Explain the concept of a "conjugate acid" and a "conjugate base" in the context of acid-base reactions.
a conjugate acid is the species formed after the base accepts a proton.
Based on its electron configuration, which group on the periodic table would you expect element X with the configuration [Ar] 4s2 3d10 4p5 to be in?
17th group
How does the quantum mechanical model of the atom differ from earlier models like the bohr model?
the electron is treated mathematically as a wave.
What is the smallest unit of matter that cannot be broken down further, and how are elements on the periodic table classified based on this unit?
An atom, atomic number.