Adding or removing neutrons from the nucleus are how isotopes are created. Protons carry a positive electrical charge and they alone determine the charge of the nucleus.
Adding or removing protons from the nucleus changes the charge of the nucleus and changes that atom's atomic number. So, adding or removing protons from the nucleus changes what element that atom is! Electron affinities are measured in the gaseous state. In general, electron affinities become more negative as we move from left to right on the periodic table.
In general, electron affinities become less negative from top to bottom of a group. What does a negative energy imply? Why is the electron affinity value for fluorine less than that of chlorine? Describe the general trend for electron affinity values moving from left to right on the periodic table. Describe the general trend for electron affinity values moving from top to bottom in a group on the periodic table. Why is more energy released in the formation of a halide ion than with other elements?
Licenses and Attributions. CC licensed content, Shared previously. This is more subtle and more difficult to explain in words alone. See Figure Here we see positive charge on the rod pulling negative charge to the nearby metal surface of the electroscope leaving positive charge on the two leafs. Note that the total charge on the electroscope is zero. What has happened is that the charge gets rearranged as a result of the rod being placed nearby.
This suggests that the charge on the rod affects the nearby environment so that charge in the electroscope "feels" its presence. What happens is that an electric field is created by the charge on the rod. This electric field influences the distribution of charge on the electroscope. We made sparks fly across a gap between two metal spheres.
Electrons were transferred by a rotating belt on to one of the spheres. As described above, the charges create an electric field which spans the space between the two spheres.
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? Most metals become cations when they make ionic compounds.
A neutral sodium atom is likely to achieve an octet in its outermost shell by losing its one valence electron. The outermost shell of the sodium ion is the second electron shell, which has eight electrons in it. The octet rule has been satisfied. Some atoms have nearly eight electrons in their valence shell and can gain additional valence electrons until they have an octet.
When these atoms gain electrons, they acquire a negative charge because they now possess more electrons than protons. Negatively charged ions are called anions.
0コメント