Question

In your own words, define or explain these terms or symbols: (a) \(\underset{\mathbf{Z}}{\mathbf{A}} \mathbf{E} ;\) (b) \(\boldsymbol{\beta}\) particle; \(\mathbf{( c )}\) isotope; \(\mathbf{( d )}^{16} \mathbf{O}\) (e) molar mass.

Short answer

(a) \(\underset{\mathbf{Z}}{\mathbf{A}} \mathbf{E}\) is a symbol used to denote isotopes of an element E, where A is the mass number and Z is the atomic number. (b) A \(\boldsymbol{\beta}\) particle is a charged particle emitted in beta decay. (c) An isotope is a form of a chemical element with the same number of protons but a different number of neutrons. (d) \(^{16} \mathbf{O}\) is an isotope of oxygen with 8 protons and 8 neutrons. (e) Molar mass is the mass in grams of one mole of a substance.

Step-by-step solution

Understand \(\underset{\mathbf{Z}}{\mathbf{A}} \mathbf{E}\)

This notation is used in nuclear physics and chemistry to denote different isotopes of an element. E stands for the element under consideration. The letter A at the upper position denotes the mass number of the isotope, which is the total number of protons and neutrons in the nucleus. At the lower position, the letter Z represents the atomic number of the isotope, which is the number of protons in the nucleus.

Define \(\boldsymbol{\beta}\) particle

\(\boldsymbol{\beta}\) particle refers to a charged particle that is emitted in a type of radioactive decay called beta decay. There are two types of beta particles: \(\beta^-\) particles, which are electrons, and \(\beta^+\) particles, which are positrons.

Define isotope

An isotope is a form of a chemical element whose atomic nucleus contains a specific number of neutron(s) in addition to the number of protons that is unique to the element. Different isotopes of the same element have the same atomic number (number of protons in the nucleus) but different mass numbers due to the different numbers of neutrons.

Identify \(^{16} \mathbf{O}\)

The notation \(^{16} \mathbf{O}\) denotes a particular isotope of oxygen. The number 16 represents the mass number - the total amount of protons and neutrons in the nucleus of the atom. Therefore, an atom of \(^{16} \mathbf{O}\) has 8 protons (as the atomic number of oxygen is 8) and 8 neutrons.

Define molar mass

Molar mass is the mass in grams of one mole (6.022 x 10^23 particles) of a substance. It has the units gram per mole (g/mol). The molar mass of an element is numerically equivalent to the element's relative atomic mass.

Key concepts

Isotopes

Atoms are like special puzzles, each one made up of a unique number of protons, neutrons, and electrons. When scientists talk about isotopes, they refer to the different versions of the same element that exist. These versions all have the same number of protons in their nuclei but differ in the number of neutrons. This means isotopes of an element share the same atomic number but have different mass numbers. These mass numbers tell us the total count of protons and neutrons together.

Think of carbon, a common example. Carbon has several isotopes, like carbon-12 and carbon-14. Both have 6 protons because that's what makes them carbon, but carbon-12 has 6 neutrons, whereas carbon-14 contains 8 neutrons.

• Same atomic number (number of protons)
• Different number of neutrons
• Different mass numbers

Understanding isotopes is key in fields like chemistry and physics, as they help explain things such as radioactive decay, where some isotopes can change into others.

Beta Decay

Beta decay is a fascinating process in the world of nuclear chemistry. It involves the transformation of a neutron into a proton or vice versa within an atomic nucleus. During this process, a beta particle is emitted. Beta particles come in two types: beta-minus (β⁻) and beta-plus (β⁺) particles.

In beta-minus decay, a neutron turns into a proton. As a result, an electron, which is the β⁻ particle, is ejected from the nucleus. This process increases the atomic number by one but keeps the mass number the same. For example, carbon-14 undergoes β⁻ decay to become nitrogen-14.

In beta-plus decay, a proton is converted into a neutron, releasing a positron, the β⁺ particle. This action decreases the atomic number by one, again without altering the mass number. An isotope like oxygen-15 can undergo β⁺ decay to form nitrogen-15.

• Beta particle types: β⁻ (electron), β⁺ (positron)
• Beta-minus increases atomic number
• Beta-plus decreases atomic number

Beta decay is essential for understanding nuclear reactions and plays a crucial role in applications ranging from medical imaging to understanding the age of archaeological finds.

Molar Mass

In chemistry, molar mass acts as a bridge connecting the tiny atomic scale to quantities we can measure and observe. Molar mass is the mass of one mole of a substance, measured in grams per mole (g/mol). One mole is a basic unit in chemistry that represents a quantity of an element or compound—specifically, 6.022 x 10²³ particles, which is known as Avogadro's number.

Each element on the periodic table has a molar mass, which can usually be found underneath the element symbol. This mass tells us how much one mole of that element weighs in grams. For example, carbon has a molar mass of about 12.01 g/mol, according to its average atomic mass. This number helps chemists know how much of a substance is needed to react with another quantitatively.

• Mass of one mole in g/mol
• Uses Avogadro's number, 6.022 x 10²³
• Crucial for stoichiometry in reactions

Understanding molar mass allows scientists to work with chemical equations and predict how substances will react and in what amounts.