How does atoms work

Often, the resulting number contains a decimal. For example, the atomic mass of chlorine Cl is Given an atomic number Z and mass number A , you can find the number of protons, neutrons, and electrons in a neutral atom. Isotopes are various forms of an element that have the same number of protons, but a different number of neutrons.

Isotopes are various forms of an element that have the same number of protons but a different number of neutrons. Some elements, such as carbon, potassium, and uranium, have multiple naturally-occurring isotopes. Isotopes are defined first by their element and then by the sum of the protons and neutrons present. While the mass of individual isotopes is different, their physical and chemical properties remain mostly unchanged.

Isotopes do differ in their stability. Carbon 12 C is the most abundant of the carbon isotopes, accounting for Carbon 14 C is unstable and only occurs in trace amounts. Neutrons, protons, and positrons can also be emitted and electrons can be captured to attain a more stable atomic configuration lower level of potential energy through a process called radioactive decay.

The new atoms created may be in a high energy state and emit gamma rays which lowers the energy but alone does not change the atom into another isotope. These atoms are called radioactive isotopes or radioisotopes. Carbon is normally present in the atmosphere in the form of gaseous compounds like carbon dioxide and methane. Carbon 14 C is a naturally-occurring radioisotope that is created from atmospheric 14 N nitrogen by the addition of a neutron and the loss of a proton, which is caused by cosmic rays.

This is a continuous process so more 14 C is always being created in the atmosphere. Once produced, the 14 C often combines with the oxygen in the atmosphere to form carbon dioxide.

Carbon dioxide produced in this way diffuses in the atmosphere, is dissolved in the ocean, and is incorporated by plants via photosynthesis. Animals eat the plants and, ultimately, the radiocarbon is distributed throughout the biosphere. In living organisms, the relative amount of 14 C in their body is approximately equal to the concentration of 14 C in the atmosphere.

When an organism dies, it is no longer ingesting 14 C, so the ratio between 14 C and 12 C will decline as 14 C gradually decays back to 14 N. This slow process, which is called beta decay, releases energy through the emission of electrons from the nucleus or positrons.

After approximately 5, years, half of the starting concentration of 14 C will have been converted back to 14 N. This is referred to as its half-life, or the time it takes for half of the original concentration of an isotope to decay back to its more stable form. The protons and the neutrons make up the center of the atom called the nucleus and the electrons fly around above the nucleus in a small cloud. The electrons carry a negative charge and the protons carry a positive charge.

In a normal neutral atom the number of protons and the number of electrons are equal. Physical Science. Atoms are in your body, the chair you are sitting in, your desk and even in the air.

See more nuclear power pictures. Cite This! Print Citation. Try Our Crossword Puzzle! Atoms are the basic units of matter and the defining structure of elements. The term "atom" comes from the Greek word for indivisible, because it was once thought that atoms were the smallest things in the universe and could not be divided.

We now know that atoms are made up of three particles: protons, neutrons and electrons — which are composed of even smaller particles, such as quarks. Atoms were created after the Big Bang As the hot, dense new universe cooled, conditions became suitable for quarks and electrons to form.

Quarks came together to form protons and neutrons, and these particles combined into nuclei. This all took place within the first few minutes of the universe's existence, according to CERN. It took , years for the universe to cool enough to slow down the electrons so that the nuclei could capture them to form the first atoms.

The earliest atoms were primarily hydrogen and helium , which are still the most abundant elements in the universe, according to Jefferson Lab. Gravity eventually caused clouds of gas to coalesce and form stars, and heavier atoms were and still are created within the stars and sent throughout the universe when the star exploded supernova. Protons and neutrons are heavier than electrons and reside in the nucleus at the center of the atom.

Electrons are extremely lightweight and exist in a cloud orbiting the nucleus. The electron cloud has a radius 10, times greater than the nucleus, according to the Los Alamos National Laboratory.

Protons and neutrons have approximately the same mass. However, one proton is about 1, times more massive than an electron. Atoms always have an equal number of protons and electrons, and the number of protons and neutrons is usually the same as well. Adding a proton to an atom makes a new element, while adding a neutron makes an isotope, or heavier version, of that atom.

The nucleus was discovered in by Ernest Rutherford, a physicist from New Zealand.