Atom - Wikipedia
网页Atoms are the basic particles of the chemical elements. An atom consists of a nucleus of protons and generally neutrons, surrounded by an electromagnetically bound swarm of electrons. The chemical elements are distinguished from each other by the number of protons that are in their atoms. For example, any atom that contains 11 protons is sodium ...
Atom | Definition, Structure, History, Examples, Diagram, & Facts
网页2024年8月17日 · 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 inch). A convenient unit of length for measuring atomic sizes is the angstrom (Å), defined as 10 −10 metre. The radius of an atom measures 1–2 Å.
What Is an Atom? Atom Definition - Science Notes and Projects
网页2023年11月19日 · Atoms are incredibly small, typically around 100 picometers in diameter. About 99.94% of an atom’s mass is in its nucleus, with protons and neutrons being almost 2,000 times heavier than electrons. If all of an atom’s components froze in time, its volume would be around 99.9999% empty space. This is because the electrons are tiny compared ...
Atoms - What are they? What's inside them? - Explain that Stuff
网页2024年1月24日 · Atoms aren't just packets of matter: they contain electrical energy too. Each proton in the nucleus of an atom has a tiny positive charge (electricity that stays in one place). We say it has a charge of +1 to make everything simple (in reality, a proton's charge is a long and complex number: +0.00000000000000000016021892 C, to be exact ...
原子 - 维基百科，自由的百科全书
网页原子 （英語： atom）是构成 化學元素 的 普通物质 （英语：Matter#Definition）[2][3] 的最小单位 [4]；原子也是 化学变化 中最小的粒子及元素 化学性质 的最小單位。. 一粒正原子包含有一粒緻密的 原子核 及若干圍繞在原子核周圍帶負電的 电子。. 而反原子的原子核 ...
Periodic Table - Ptable
网页Interactive periodic table showing names, electrons, and oxidation states. Visualize trends, 3D orbitals, isotopes, and mix compounds. Fully descriptive writeups.
What is an atom - NRC
网页2020年3月19日 · Two atoms with an identical number of protons in their nuclei belong to the same element. An element, like hydrogen, oxygen or iron, is a substance that cannot be broken down—outside of a nuclear reaction—into anything else. In other words, one element cannot be transformed into another (again, with the exception of nuclear reactions).
Build an Atom - Atoms | Atomic Structure | Isotope Symbols - PhET ...
网页Build an atom out of protons, neutrons, and electrons, and see how the element, charge, and mass change. Then play a game to test your ideas!
Atoms and molecules - BBC Bitesize
网页Atoms can form strong bonds with each other, making molecules close molecule Two or more atoms which are strongly bonded together. The smallest particle of a substance that has all of the physical ...
2.1: Atomic Theory and the Structure of Atoms
网页Atoms and subatomic particles are so small that it doesn't quite make sense to measure their masses in grams. A more useful unit to measure atomic mass is the atomic mass unit (\(\text{amu}\)), where 1 amu = 1.660539 × 10 −24 g or one-twelfth of the mass of a carbon-12 atom. As you can see in the table above, the mass of 1 proton and 1 neutron are each 1 amu in this system.