Answer:
Permanent Magnets are always magnetic.
Temporary Magnets loose their magnetizing power after the source is removed. (outside a magnetic field)
Electromagnets are made by sending electric coil around an iron rod. (I.e. Nail, coil, and batteries can pick up paperclips)
Answer: Option (D) is the correct answer.
Explanation:
Atomic number of chlorine is 17 and its electronic distribution is 2, 8, 7.
So, in order to attain stability it tends to gain one electron from a donor atom. Therefore, a chlorine ion is formed as 
.
As it gains only one electron that is why, -1 charge occurs.
Whereas Ar is a noble gas with atomic number 18. As it has completely filled octet so it will be unreactive in nature as it is already stable.
Similarly, He is also a noble gas so it is unreactive in nature.
Atomic number of boron (B) is 5 with electronic distribution 2, 3. So, in order to attain stability it needs to lose 3 electrons.
Thus, we can conclude that Cl is the atom which tends to gain 1 valence electron from another atom in order to become stable.
Answer: A
Explanation: i took the test
Answer: First, here is the balanced reaction: 2C4H10 + 13O2 ===> 8CO2 + 10H2O.
This says for every mole of butane burned 4 moles of CO2 are produced, in other words a 2:1 ratio.
Next, let's determine how many moles of butane are burned. This is obtained by
5.50 g / 58.1 g/mole = 0.0947 moles butane. As CO2 is produced in a 2:1 ratio, the # moles of CO2 produced is 2 x 0.0947 = 0.1894 moles CO2.
Now we need to figure out the volume. This depends on the temperature and pressure of the CO2 which is not given, so we will assume standard conditions: 273 K and 1 atmosphere.
We now use the ideal gas law PV = nRT, or V =nRT/P, where n is the # of moles of CO2, T the absolute temperature, R the gas constant (0.082 L-atm/mole degree), and P the pressure in atmospheres ( 1 atm).
V = 0.1894 x 0.082 x 273.0 / 1 = 4.24 Liters.
Explanation:
Answer: D) More moles of ions are present in a given volume of 0.10 M 
than in the same volume of 0.10 M NaCl.
Explanation:
A electrolyte is a solution that dissociates completely when dissolved in water. The ions act as good conductors of electric current in the solution.
More is the number of ions , more will be the conductance and hence the solution will be a better conductor of electricity.
0.10 M aqueous solution of is a better conductor of electricity as it dissociates to give three ions whereas 0.10 M aqueous solution of 
dissociates to give two ions only.
Thus 0.10 M aqueous solution of sodium sulfate, , is a better conductor of electricity as more moles of ions are present in a given volume of 0.10 M than in the same volume of 0.10 M
