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The total pressure exerted by a mixture of gases is equal to the sum of the partial pressures of the gases in the mixture. The pressure exerted by an individual gas in a mixture is known as its partial pressure. Learn more about this and how to calculate the partial pressure and the mol fraction of a component in a gas mixture! Check out my Instagram :) krisztinavoronova

Nuclear reactions in which a nucleus decays spontaneously: alpha and beta decay, positron emission and electron capture. In a nuclear transmutation, a nucleus reacts with a subatomic particle or another nucleus to form a product nucleus that is more massive than the starting material. Nuclear transmutation reactions occur only under very special conditions, such as the collision of a beam of hi...

Radioactive decay is a first-order process. The time required for half of the nuclei in any sample of a radioactive isotope to decay is a constant, called the half-life of the isotope. Because nuclear decay follows first-order kinetics, it has a rate constant independent of temperature, and the chemical or physical environment, we can use the half-lives of isotopes to estimate the ages of geolo...

Any atom with more than one proton (anything but H) will have repulsions between the protons in the nucleus. The concept of nuclear stability helps us identify the stability of an isotope using two main factors: neutron-to-proton ratio and the total number of nucleons in the nucleus. For smaller nuclei (Z ≤ 20) stable nuclei have a neutron-to-proton ratio close to 1:1. As nuclei get larger, it ...

Some nuclei change spontaneously, emitting radiation. They are said to be radioactive (radionuclides). There are several ways radionuclides can decay into a different nuclide, and we use nuclear equations to show how these nuclear reactions occur. In chemical equations, atoms and charges need to balance. In nuclear equations, the atomic number and the mass number need to balance. Types of radia...

Both the enthalpy (ΔH), entropy (ΔS), and the temperature plays a role in determining whether a process is spontaneous. The change in Gibbs free energy (ΔG) can predict the direction of the chemical reaction under constant temperature and constant pressure conditions: ∆𝐺=∆𝐻−𝑇∆𝑆 If ΔG is negative, the forward reaction is spontaneous. If ΔG is 0, the system is at equilibrium. If ΔG is positive, t...

The entropy of a pure crystalline substance at absolute zero is 0. Learn more about the Third Law of Thermodynamics and how to calculate reaction entropy. Also, check out my Instagram :) krisztinavoronova

Entropy, S, is a measure of the randomness or disorder of a system. The Second Law of Thermodynamics states that the entropy of the universe, as an isolated system, will always increase over time. So, the entropy of the universe can never be negative. Because all real processes are irreversible, they will result in an increase in entropy of the universe. Also, check out my Instagram :) instagra...

Spontaneous processes proceed without any outside assistance. Processes that are spontaneous in one direction are nonspontaneous in the reverse direction. Don’t confuse spontaneous with fast or nonspontaneous with impossible. Energy can be used to make some reactions spontaneous that otherwise would not be. Reversible process: the system changes so that the system and surroundings can be return...

Learn how to calculate the quantity of CO2, a greenhouse gas, released from combustion of gasoline! Check out these awesome videos on climate change Climate Change by SciShow: ruclips.net/video/M2Jxs7lR8ZI/видео.html 13 Misconceptions About Global Warming by Veritasium: ruclips.net/video/OWXoRSIxyIU/видео.html Also, check out my Instagram :) krisztinavoronova

Air pollution refers to the introduction of substances into the atmosphere that have harmful effects on humans, other living organisms, and the environment. Learn more about acid rain and photochemical smog. Check out this video by SciShow on the fog that killed 12,000 people 😯: ruclips.net/video/4fkcTA7YX44/видео.html Also, check out my Instagram :) krisztinavoronova

The ozone layer occurs in the stratosphere, at an altitude of about 25 km. Ozone absorbs much of the radiation between 240 and 310 nm, protecting us from UV radiation. It forms from the reaction of molecular oxygen with the oxygen atoms produced in the upper atmosphere by photodissociation. The photodissociation of ozone reverses the reaction that forms it: so, we have an ozone formation and de...

The atmosphere consists of the troposphere, stratosphere, mesosphere, and thermosphere. The temperature varies greatly and the pressure decreases with increasing altitude. The main components of air is nitrogen and oxygen gas. Learn how to calculate the concentration of trace gasses in the atmosphere in units of ppm. Also, check out my Instagram :) krisztinavoronova

The outer layer of the atmosphere defends us from the hail of radiation and high-energy particles that continuously bombard Earth. For a chemical change to occur when radiation strikes atoms or molecules: a) the incoming photons must have sufficient energy to break a chemical bond (photodissociation) or remove an electron from the atom or molecule (photoionization); b) the atoms or molecules be...

Solubility equilibria and the solubility-product constant, Ksp.

Buffer capacity. The pH of buffer solutions after the addition of a strong acid or base.

pH of buffer solutions: the Henderson-Hasselbalch equation.

What is a Buffer Solution?

The common-ion effect. Calculate the pH of a solution containing a weak acid and its conjugate base.

Acid-Base Properties of Salts with Examples

Acid- and Base-Dissociation Constants for Conjugate Acid-Base Pairs with Examples

How to calculate the pH from the Acid-Dissociation Constant, Ka?

Weak Acids, the Acid-Dissociation Constant. How to Calculate the Acid-Dissociation Constant from pH?

Autoionization of Water, the Ion-Product Constant, and the pH Scale with Examples

Conjugate Acid-Base Pairs and Strengths of Acids and Bases with Examples

What is an acid and a base? Arrhenius, Brønsted-Lowry, and Lewis acids and bases

Le Chatelier’s Principle Explained with Examples

Equilibrium Expression for Homogeneous vs. Heterogeneous Equilibria

How to Calculate Equilibrium Concentrations from the Equilibrium Constant? | Example!