物质有许多定义，但最常见的是它是任何具有质量和占据空间的物质。所有物理对象都是由原子形式的物质组成，而原子又由质子，中子和电子组成。物质由构成块或粒子组成的想法起源于希腊哲学家德谟克利特（公元前470-380）和Leucippus（公元前490年）。物质是由原子构建的。最基本的原子，称为prot的氢的同位素，是一个质子。因此，尽管亚原子粒子并不总是被某些科学家视为物质的形式，但您可以将Protium视为例外。有些人认为电子和中子也是物质的形式。否则，任何由原子构成的物质都是由物质组成的。例子包括：原子（氢，氦，cal，铀）。分子（水，臭氧，氮气，蔗糖）。离子（Ca2 +，SO42-）。聚合物和大分子（纤维素，几丁质，蛋白质，DNA）。混合物（油和水，盐和沙子，空气）。复杂形式（椅子，行星，球）。虽然质子，中子和电子是原子的组成部分，但这些粒子本身都是基于费米子。夸克和轻子通常不被认为是物质的形式，尽管它们确实符合该术语的某些定义。在大多数情况下，最简单地说明物质由原子组成。反物质仍然是物质，虽然粒子在彼此接触时消灭普通物质。反物质天然存在于地球上，尽管数量极少。物质可以存在于各个阶段：固体，液体，气体或等离子体。大多数物质可以基于材料吸收（或损失）的热量在这些相之间转变。物质还有其他状态或阶段，包括玻色 – 爱因斯坦凝聚物，费米子凝聚物和夸克 – 胶子等离子体。请注意，虽然物质具有质量，而大量物体包含物质，但这两个术语并不完全是同义词，至少在物理学中是这样。物质不是守恒的，而质量在封闭系统中是守恒的。根据狭义相对论，封闭系统中的物质可能会消失。另一方面，质量可能永远不会被创造或破坏，尽管它可以转化为能量。质量和能量之和在封闭系统中保持不变。在物理学中，区分质量和物质的一种方法是将物质定义为由表现出静止质量的粒子组成的物质。即便如此，在物理和化学中，物质表现出波粒二象性，因此它具有波和粒子的特性。
新加坡南洋理工大学物理学Assignment代写：关于物质的定义
Matter has many definitions, but the most common is that it is any substance which has mass and occupies space. All physical objects are composed of matter, in the form of atoms, which are in turn composed of protons, neutrons, and electrons. The idea that matter consisted of building blocks or particles originated with the Greek philosophers Democritus (470-380 BC) and Leucippus (490 BC). Matter is built from atoms. The most basic atom, the isotope of hydrogen known as protium, is a single proton. So, although subatomic particles aren’t always considered forms of matter by some scientists, you could consider Protium to be the exception. Some people consider electrons and neutrons to also be forms of matter. Otherwise, any substance built of atoms consists of matter. Examples include: Atoms (hydrogen, helium, californium, uranium).Molecules (water, ozone, nitrogen gas, sucrose). Ions (Ca2+, SO42-). Polymers and Macromolecules (cellulose, chitin, proteins, DNA) .Mixtures (oil and water, salt and sand, air). Complex Forms (a chair, a planet, a ball). While protons, neutrons, and electrons are the building blocks of atoms, these particles are themselves based on fermions. Quarks and leptons typically aren’t considered forms of matter, although they do fit certain definitions of the term. At most levels, it’s simplest to state simply that matter consists of atoms. Antimatter is still matter, although the particles annihilate ordinary matter when they contact each other. Antimatter exists naturally on Earth, although in extremely small quantities. Matter can exist in various phases: solid, liquid, gas, or plasma. Most substances can transition between these phases based on the amount of heat the material absorbs (or loses). There are additional states or phases of matter, including Bose-Einstein condensates, fermionic condensates, and quark-gluon plasma. Note that while matter has mass, and massive objects contain matter, the two terms are not exactly synonymous, at least in physics. Matter is not conserved, while mass is conserved in closed systems. According to the theory of special relativity, matter in a closed system may disappear. Mass, on the other hand, may never have been created nor destroyed, although it can be converted into energy. The sum of mass and energy remains constant in a closed system. In physics, one way to distinguish between mass and matter is to define matter as a substance consisting of particles that exhibit rest mass. Even so, in physics and chemistry, matter exhibits wave-particle duality, so it has properties of both waves and particles.