Solution: (i) Density (ii) thermal
Liquids at lower temperatures have greater density when compared to liquids at higher temperatures.This is because, at higher temperatures, molecules have greater kinetic energy and hence they are spaced farther apart, when compared to molecules at lower temperatures. Thus, the colder layers of liquids are heavier than the warmer layers, which causes then to move down due to gravity. For the same reason, the hotter layers move upwards through the liquid.
When a liquid is heated, the molecules closest to the heat source have greater energy, their density becomes less and they move upwards. The colder layers sink downwards. The layers of the liquid which were cold initially, get heated and they travel upwards. As the process repeats, convection currents are set up in the liquid.
These currents transfer the thermal energy derived from the source throughout the liquid. The process stops when the entire liquid is at the same temperature.
Thus, convection currents occur in liquids due to temperature and <u>density</u> differences. Convection currents transfer <u>thermal</u> energy throughout a fluid.
Answer: Ionization energy is the amount of energy necessary to <u>remove an electron from an atom</u>
Explanation:
Ionization consists of the production of ions, which are electrically charged atoms or molecules due to the excess or lack of electrons with respect to a neutral atom or molecule.
In this sense, ionization energy is the <u>energy necessary to separate (remove) an electron from a gaseous atom</u>, isolated and in a fundamental state. This is because <u>electrons are strongly attracted to the nucleus and it is necessary to provide energy to separate them</u>. However, where the atom always loses electrons is in the last layer, which is where the weakest electrons are attracted to the nucleus.
Material composing the body,
temperature of the body and the length of the body affects the electrical
resistance of a body. Bodies directly surrounding the body will not affect the
electrical resistance of the body. The answer is letter D.
Answer: 4 moles of
Explanation: The given compound is an ionic compound formed by combination of sodium as a metal and sulphite as polyatomic anion.
It is formed by the combination of and .
Thus 1 mole of contains 2 atoms of sodium, 1 atom of sulphur and 3 atoms of oxygen.
The 4 represents that 4 moles of are present which contains 8 atoms of sodium, 4 atom of sulphur and 12 atoms of oxygen.