Dec 8, Explanation: Elements are classified on the basis of Z , the atomic number , which specifies the number of massive, positively-charged, nucular particles, i. Related questions How do I determine the molecular shape of a molecule? What is the lewis structure for co2?
The electrons jump the gap and settle on the other sphere which is grounded. Grounding has to do with establishing an electrical connection to the earth which has the effect of neutralizing the electrical charge on an object. The flow of electrons between spheres results in the spark we see. But do we actually see the electrons? No, what we see results from the electrons striking atoms in the air between the spheres.
The struck atoms become "excited" and when the atoms jump back to a deexcited state they emit light. That is what we see as the spark.
We are able to attract a metal can or even a large delicately balanced wood plank with charges on a rubber rod. We explain this by noting, as we explained the electroscope, that the presence of charge creates an electric field.
The electric field influences the distribution of charge within the metal can, or even on the atoms in the wood. A negative charge has the effect of drawing positive charge closer to it, and a positive charge draws negative charge closer to it.
The net effect is to create an attractive force. Electric fields are illustrated in the animation we access here. We observe electrons in the environment of an electric field caused by two much larger charged objects, one positive and one negative. Note how a field is created by the charges. In short, all atoms with a particular number of protons belong to the same element. The number of protons in an atom is denoted by the atomic number , which is shown as a number in the periodic table, usually shown above the chemical symbol of the element.
Then, the atomic numbers above each element in the periodic table show the number of protons of each element. Since atoms are electrically neutral they carry the same number of protons as electrons ; then, the number of protons tells us the number of electrons an element has.
For example, nitrogen N has an atomic number of 7 see the periodic table below. Then, nitrogen must have seven protons, and it must also have seven electrons.
Sodium Na has an atomic number of is 11; then, sodium must have eleven protons, and it must also have eleven electrons. The same applies to all elements in the periodic table. The actual mass of an atom is known as its weight on planet Earth. Then, we consider atomic weight and mass number as the same. The atomic mass of an element is mostly the mass of its neutrons and its protons since electrons have a negligible mass.
For example, the atomic mass of carbon C is This comes from adding the number of protons 6 plus the number of neutrons 6 , each of which weighs 1 amu.
The atomic mass is shown as a decimal number called the mass number in the periodic table, usually shown below the chemical symbol of the element. For the objectives of this course, we consider atomic weight and atomic mass to mean the same thing and ignore the decimal points in the mass number. What is the atomic number of an element? What is the mass number of an element?
How are atomic number, number of protons and number of electron related? How are mass number, number of protons and number of neutrons related? The first shell can carry up to two electrons, the second shell can carry up to eight electrons, and the third shell [can carry up to eighteen electrons but] is usually filled with up to eight electrons. For example, the atomic number of nitrogen is 7. This means that nitrogen has seven protons, and therefore has seven electrons.
Two electrons fill the first orbital shell, and five electrons go to the second orbital shell. This means that hydrogen has one proton, and also one electron, which goes to the first shell. The first two fill the first orbital shell, eight more fill the second orbital shell, and the last electron goes to the third orbital shell.
Single atoms by themselves are unstable and chemically reactive unless their outermost electron shell is already filled with electrons. This operation yields the number of excess protons. A similar process is used to determine the total charge of a negatively charged object an object with an excess of electrons , except that the number of protons is first subtracted from the number of electrons.
In conclusion, an electrically neutral object is an object that has a balance of protons and electrons. In contrast, a charged object has an imbalance of protons and electrons.
Determining the quantity of charge on such an object involves a counting process ; the total number of electrons and protons are compared to determine the difference between the number of protons and electrons.
This difference is multiplied by 1. The type of charge positive or negative is determined by whether the protons or the electrons are in excess. Use your understanding of charge to answer the following questions. When finished, click the button to view the answers. Negatively charged objects have protons; it's just their number of electrons is greater than their number of protons. Electrically neutral atoms simply possess the same number of electrons as protons.
This gives the objects a balance of both type of charge. Identify the following particles as being charged or uncharged. If charged, indicate whether they are charged positively or negatively. See Answer Answers: a. Charged Negatively.
There are 11 electrons and 10 protons. This results in an imbalance of charge. With more electrons than protons, the particle is negatively charged. There are 11 electrons and 11 protons. This results in a balance of charge.
This particle is neutral or uncharged. There are 18 electrons and 20 protons. With more protons than electrons, the particele is positively charged. Consider the graphic at the right of a neutral oxygen atom. Answers: a. Gain electrons AND b. Lose electrons. Protons are tightly bound in the nucleus and can be neither gained nor loss.
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