To determine mass of the given number of atoms of mercury, we need a factor that would relate the number of atoms to number of moles. In this case, we use the Avogadro's number. It is a <span>number that represents the
number of units in one mole of any substance. This has the value of 6.022 x
10^23 units / mole. The number of units could be atoms, molecules, ions or electrons. To convert into mass, we use the given amu of mercury since it is equal to grams per mole. We calculate as follows:
</span>3.0 x 10^10 atoms ( 1 mol / 6.022 x 10^23 atoms ) ( 200.59 g / 1 mol ) = 9.99x10^-12 g Hg
Answer:
Explanation:
Filtration followed by evaporation:
To separate the mixture of sand and sugar, it is best to use the separation technique of filtration then evaporation.
Pour the water into the mixture. The sugar will dissolve with time in the water. Sand is made up of quartz and does not dissolve in water.
After the dissolution, filter the solution to separate the sand using a filter paper.
Dry the sand thereafter then proceed to evaporate the sugar with water solution. Evaporation will turn water into vapor and the sugar crystals will be left behind.
Answer:Cell reaction is going forward.
Explanation:
For any chemical reaction to be spontaneous or to move in forward direction the ΔG ,the Gibbs free energy must be negative.
The cell potential of a battery is positive for a spontaneous reaction, so for a battery to give output its cell potential must be positive.
Thermodynamics and electro-chemistry are related in the following manner:
ΔG=-nFE
n=number of electrons involved
F=Faradays constant
E=cell pottential of battery
so from the above equation ΔG would only be negative when E cell that is the cell potential is positive.
For a battery which is being used its cell potential is positive and hence the ΔG would be negative. So the cell reaction occurring would be in forward direction as ΔG is negative.
when the cell potential Ecell is 0 then ΔG is also zero then the reaction occurring in battery would be at equilibrium.
When the cell potential Ecell is - then ΔG is positive and the reaction would be occurring backwards.
<u>¹⁴₇N</u><u> </u>is the more stable isotope
<h3>
Briefly explained</h3>
We have ¹⁴₇N which has a neutron to proton ratio of one, and we look at ¹⁸₇N which has a neutron to proton ratio of 1.57 Again, you look at table 24 to and you see the atomic number of seven and there is really no stable isotope. It has any more than 10 neutrons.
When we have eight, protons will go down seven protons. There's really nothing stable that has more than maybe eight neutrons. So the fact that we have 11 neutrons with ¹⁸₇N suggests that this is very unstable and
¹⁴₇N is the stable isotope of the pair.
<h3>
Stable and Unstable Nuclei</h3>
An atom is electrically neutral. It contains an equal number of positively charged protons and negatively charged electrons and their charges balance. The nucleus however contains only positively charged protons which are closely packed together in a very small volume (remember neutrons have no charge).
From the laws of physics (Coulomb’s Law) one would expect that the protons being of the same charge and so close together would exert strong repulsive forces on each other. The combined gravitational force from the protons and neutrons in a nucleus is insignificant as an attractive force because their masses are so tiny.
This implies there must be an additional attractive force similar in size to the electrostatic repulsion which holds the nucleus together.
Learn more about stable and unstable nuclei
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Chemical weathering is when things get weathered chemically