听力原文: What is an atom? The modern view of an atom has come from many fields of chemistry and physics. The idea of an atom came from ancient Greek science and philosophy and from the results of 18th and 19th century chemistry. It includes three aspects, concept of the atom, ...
How Big Is an Atom? Atoms have great variations in weight, although they are all about the same size. The diameter of an atom is a million times smaller than one strand of thick human hair, very tiny indeed. The diameters of atoms range from approximately 0.1 to 0.5 nanometers. For exa...
Scientists used to believe that there was no smaller particle of matter than the atom, even before conclusively proving the atom existed. Through more advanced techniques, they discovered that there were smaller units of matter, such as the proton, neutron, and electron. Over the past century, ...
are made up of different atoms and each type of atom has the chemical characteristics of its respective element.Answer and Explanation: The nucleus of an atom is the dense core that is located at the center of the atom. The nucleus is composed of positively charged particles called......
Thomson provided the first hint that an atom is made of even smaller particles. Can we see an atom? Atoms are really small. So small, in fact, that it's impossible to see one with the naked eye, even with the most powerful of microscopes. ... Now, a photograph shows a single atom...
disturbed. Rutherford was able to approximate the size of the nucleus of the gold atom, finding it to be at least 10,000 times smaller than the size of the entire atom with much of the atom being empty space. Rutherford's model of the atom is still the basic model that is used today...
To fully understand matter let's look at the atom. It is now generally accepted that atoms are made up of three particles called neutrons, protons, and electrons. The neutrons and protons are found in the nucleus (center) of the atom and the electrons reside in a shell surrounding the nuc...
All matter consists of atoms, which, in turn, consist of protons, neutrons and electrons. Both protons and neutrons are located in the nucleus, which is at the center of an atom. Protons are positively charged particles, while neutrons are neutrally charged. Electrons are negatively charged, ...
The typical netbook buyer wants a highly portable, "smaller-than-a-laptop" system but doesn't need the speediest processor, high-capacity hard drive or other features of a bigger, heavier laptop. In short, as shown in the following table, a netbook is a compromise. ...
Located within the nucleus of the atom, a proton has a relatively larger mass than that of an electron but slightly smaller than that of a neutron. A proton will always have at least one positive charge. The proton is responsible for the atom's atomic number. The positive proton charge ba...