Search results
Atoms Definition & Molecule Definition - Atoms are the smallest particle of an element, which may or may not have an independent existence but always take part in a chemical reaction. Molecules always exist independently and retain their physical and chemical properties.
- Ether Preparation
The preparation of ethers by dehydration of alcohol is a...
- Organometallic Chemistry
What is Organometallic Chemistry? Organometallic Chemistry...
- Ammonium Dichromate
Ammonium Dichromate [(NH4)2Cr2O7] - Ammonium dichromate is a...
- K2cro4
The chromate anion is made up of one chromium atom and four...
- Glutamic Acid
It is one of the 20 amino acids. There are two types of...
- Potassium Oxide
It has valency +1 and combines readily with oxygen atoms...
- Red Phosphorus
Red phosphorus is one of the most common allotropes of...
- Chloroacetic Acid
Chloroacetic acid structure – C 2 H 3 O 2 Cl. In its solid...
- Ether Preparation
What is the difference between an atom and a molecule? An atom is the smallest particle of an element. A molecule is made of two or more atoms chemically bonded together. Atoms are...
- Overview
- Atomic model
An atom is the basic building block of chemistry. It is the smallest unit into which matter can be divided without the release of electrically charged particles. It also is the smallest unit of matter that has the characteristic properties of a chemical element.
Are all atoms the same size?
All atoms are roughly the same size, whether they have 3 or 90 electrons. Approximately 50 million atoms of solid matter lined up in a row would measure 1 cm (0.4 inches). A convenient unit of length for measuring atomic sizes is the angstrom, defined as 10−10 meters.
What does the mass of an atom consist of?
The mass of an atom consists of the mass of the nucleus plus that of the electrons. That means the atomic mass unit is not exactly the same as the mass of the proton or neutron.
How is the atomic number of an atom defined?
Most matter consists of an agglomeration of molecules, which can be separated relatively easily. Molecules, in turn, are composed of atoms joined by chemical bonds that are more difficult to break. Each individual atom consists of smaller particles—namely, electrons and nuclei. These particles are electrically charged, and the electric forces on the charge are responsible for holding the atom together. Attempts to separate these smaller constituent particles require ever-increasing amounts of energy and result in the creation of new subatomic particles, many of which are charged.
Exclusive academic rate for students! Save 67% on Britannica Premium.
Learn More
As noted in the introduction to this article, an atom consists largely of empty space. The nucleus is the positively charged centre of an atom and contains most of its mass. It is composed of protons, which have a positive charge, and neutrons, which have no charge. Protons, neutrons, and the electrons surrounding them are long-lived particles present in all ordinary, naturally occurring atoms. Other subatomic particles may be found in association with these three types of particles. They can be created only with the addition of enormous amounts of energy, however, and are very short-lived.
Jan 24, 2024 · A simple introduction to atoms. What are they made from? How do they join together to make molecules?
We made atomic bombs and generated electricity by nuclear power. We even split the atom into smaller pieces called subatomic particles. But what exactly is an atom? What is it made of? What does it look like?
Jan 6, 2021 · Learn about the parts of an atom and its history. According to the Particle Theory of Matter, all matter is made of tiny particles. These particles are either individual atoms or groups of atoms called molecules. There are two main parts to an atom. These are the nucleus and the electrons. In the center of each atom is the nucleus.
All atoms of a given element are identical; the atoms of different elements are different and have different properties; Atoms of an element are not changed into different types of atoms by chemical reactions; Compounds are formed when atoms of more than one element combine; explains the law of constant composition, law of conservation of mass
