![]() So, what gives an element its distinctive properties-what makes carbon so different from sodium or iron? The answer is the unique quantity of protons each contains. The same is true for neutrons and electrons. One proton is the same as another, whether it is found in an atom of carbon, sodium (Na), or iron (Fe). The number of protons and electrons within a neutral atom are equal, thus, the atom’s overall charge is balanced.Īn atom of carbon is unique to carbon, but a proton of carbon is not. The attraction by the positively charged nucleus helps keep electrons from straying far. This mutual attraction gives the atom some structural stability. Just as a magnet sticks to a steel refrigerator because their opposite charges attract, the positively charged protons attract the negatively charged electrons. ![]() An atom’s neutrons have no charge: they are electrically neutral. Electrons, which have a negative charge, are designated e –. Protons, with their positive charge, are designated p +. (b) In the electron cloud model, the electrons of carbon are shown in the variety of locations they would have at different distances from the nucleus over time.Īn atom’s protons and electrons carry electrical charges. (a) In the planetary model, the electrons of helium are shown in fixed orbits, depicted as rings, at a precise distance from the nucleus, somewhat like planets orbiting the sun. All the elements in your body are derived from the foods you eat and the air you breathe. Each element’s name can be replaced by a one- or two-letter symbol you will become familiar with some of these during this course. The elements in the human body are shown in, beginning with the most abundant: oxygen (O), carbon (C), hydrogen (H), and nitrogen (N). Some other elements you might be familiar with are oxygen, sodium, and iron. The elemental calcium in cheese, therefore, is the same as the calcium that forms your bones. Among these is calcium, which, because it is an element, cannot be broken down further. When you consume dairy products your digestive system breaks down the food into components small enough to cross into the bloodstream. ![]() Calcium is essential to the human body it is absorbed and used for a number of processes, including strengthening bones. A familiar example of an element that you must take in is calcium (Ca ++). While your body can assemble many of the chemical compounds needed for life from their constituent elements, it cannot make elements. An element is a pure substance that is distinguished from all other matter by the fact that it cannot be created or broken down by ordinary chemical means. A piece of cheese that weighs a pound on Earth weighs only a few ounces on the moon.Īll matter in the natural world is composed of one or more of the 92 fundamental substances called elements. In other words, weight is variable, and is influenced by gravity. An object of a certain mass weighs less on the moon, for example, than it does on Earth because the gravity of the moon is less than that of Earth. Where gravity strongly pulls on an object’s mass its weight is greater than it is where gravity is less strong. An object’s weight, on the other hand, is its mass as affected by the pull of gravity. An object’s mass is the amount of matter contained in the object, and the object’s mass is the same whether that object is on Earth or in the zero-gravity environment of outer space. An object’s mass and its weight are related concepts, but not quite the same. Scientists define matter as anything that occupies space and has mass. The substance of the universe-from a grain of sand to a star-is called matter. Explain how electrons occupy electron shells and their contribution to an atom’s relative stability.Identify the key distinction between isotopes of the same element.Distinguish between atomic number and mass number.Discuss the relationships between matter, mass, elements, compounds, atoms, and subatomic particles.By the end of this section, you will be able to:
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |