Elements and the Periodic Table Test

What is an atom?

An atom is the basic unit of matter, consisting of a nucleus made of protons and neutrons, surrounded by electrons in orbitals. Atoms are the building blocks of elements and all substances.

What is an electron?

An electron is a subatomic particle with a negative charge that orbits the nucleus of an atom. Electrons play a key role in chemical bonding and reactions.

What is a nucleus?

The nucleus is the central core of an atom, containing positively charged protons and uncharged neutrons. It is responsible for the atom's mass and plays a crucial role in nuclear reactions.

What is a proton?

A proton is a subatomic particle found in the nucleus of an atom, carrying a positive charge. Protons determine the atomic number and identity of an element.

What is energy level?

An energy level is a quantized state of an electron in an atom, where it can reside at a specific distance from the nucleus. Energy levels determine the electron's potential energy and its likelihood of being involved in chemical bonds.

What is a neutron?

A neutron is a subatomic particle located in the nucleus of an atom, carrying no charge. Neutrons contribute to the atom's mass and play a key role in stabilizing the nucleus.

What is an atomic number?

The atomic number is the number of protons found in the nucleus of an atom, which defines the element's identity and its position in the periodic table.

What is an isotope?

An isotope is a variant of a chemical element that has the same number of protons but a different number of neutrons, resulting in a different atomic mass. Isotopes can be stable or radioactive.

What is mass number?

The mass number is the total number of protons and neutrons in an atom's nucleus, reflecting its overall atomic mass. It helps distinguish between different isotopes of an element.

Atomic mass

The atomic mass is the weighted average mass of an element's isotopes, measured in atomic mass units (amu), reflecting the abundance of each isotope in nature.

Periodic Table

A tabular arrangement of chemical elements organized by increasing atomic number, where elements with similar properties are grouped together.

Period

A horizontal row in the periodic table that indicates the number of electron shells of the elements within it.

Group

A vertical column in the periodic table that contains elements with similar chemical properties and the same number of valence electrons.

Chemical symbol

A one or two-letter abbreviation used to represent a chemical element, often derived from its English or Latin name.

Plasma

A state of matter consisting of charged particles, including ions and free electrons, typically found in stars and gases at extremely high temperatures.

Nuclear Fusion

The process by which two light atomic nuclei combine to form a heavier nucleus, releasing energy in the process. This reaction powers stars, including our Sun.

Metal

A category of elements that are typically solid, malleable, ductile, and good conductors of heat and electricity. Metals are found on the left side and in the center of the periodic table.

Malleable

Capable of being shaped or bent without breaking, often referring to metals.

Ductile

Able to be stretched into a wire without breaking, primarily describing the properties of metals.

Conductivity

The ability of a material to conduct electric current or heat. In metals, high conductivity allows for efficient energy transfer.

Reactivity

The tendency of a substance to undergo chemical reactions, either by itself or with other materials.

Corrosion

The process by which metals deteriorate due to chemical reactions with their environment, often involving oxidation or rusting.

Alkali metal

A group of highly reactive metals in Group 1 of the periodic table, including lithium, sodium, and potassium, known for their reactivity with water and tendency to form strong bases.

Alkali Earth metal

A group of reactive metals in Group 2 of the periodic table, including beryllium, magnesium, and calcium, known for forming alkaline hydroxides and having two valence electrons.

Transition metal

A set of metallic elements found in Groups 3 to 12 of the periodic table, characterized by their ability to form variable oxidation states and colored compounds.

Particle accelerator

A device that uses electric and magnetic fields to accelerate charged particles to high speeds. It is used in a variety of applications, including nuclear physics, materials science, and medicine.

Nonmetal

A class of elements that are generally poor conductors of heat and electricity, often located on the right side of the periodic table. Nonmetals can exist in various states at room temperature and typically gain electrons during chemical reactions.

Diatomic molecule

A molecule composed of two atoms, which can be of the same or different chemical elements, commonly found in gases like O(2) and N(2).

Halogen

A group of highly reactive nonmetals found in Group 17 of the periodic table, which include elements like fluorine, chlorine, bromine, iodine, and astatine. They readily gain electrons to form negative ions.

Noble gas

An element that has a full valence shell, making it highly unreactive. Noble gases include helium, neon, argon, krypton, xenon, and radon, and are found in Group 18 of the periodic table.

Metalloid

An element with properties intermediate between metals and nonmetals, often exhibiting characteristics of both. Metalloids are typically semiconductors and are found along the stair-step line on the periodic table.

Semiconductor

A material that partially conducts electricity, often used in electronics and is characterized by an energy band gap between conductors and insulators.

Radioactive decay

The process by which an unstable atomic nucleus transforms into a more stable one, emitting radiation in the form of particles or electromagnetic waves.

Radioactivity

The process by which unstable atomic nuclei lose energy by emitting radiation. This can occur through various types of decay, including alpha, beta, and gamma decay.

Alpha particle

A type of radiation consisting of two protons and two neutrons, which is emitted during alpha decay of heavy nuclei.

Beta particle

A type of radiation that consists of high-energy, high-speed electrons or positrons emitted during beta decay of an atomic nucleus.

Gamma radiation

A form of high-energy electromagnetic radiation emitted from the nucleus of an atom during radioactive decay. It has no mass and no charge, making it highly penetrating.

Tracer

A chemical substance used to track or visualize processes in biological or chemical systems, often by emitting radiation.