Answer:
Corrosion
Explanation:
Silver, although known as a nobble metal, is also subject to corrosion process such as having silver tarnish when exposed to sulfur and air.
Tarnishing occurs on the surfaces of some metals such as brass, copper, and silver, which results in a corroded layer. Silver tarnish occurs from the chemical reaction that takes place when silver is exposed to sulfur which results in the formation of black Ag₂S
In order to restore the original silver surface, the silver tarnish (silver sulfide) layer is removed.
We have the statement presented here as follows;
The forks shown are made of silver (Ag). Some of the silver forks shown have lost their luster - they have become tarnished. This is an example of <u>Corrosion.</u>
<h2>Giant impact and metalcore.</h2>
Explanation :
- Mercury has a large core of liquid metal.
- The metal core is of iron metal.
- The core is surrounded by a mantle which is made up of silica and a solid outer crust.
- In the case of Mercury, the total core percentage is 42% of the planet while the Earth's core is only 17% of the planet.
- Mercury has lost part of its mantle and crust that left the mercury with a large metal core.
Answer:
0.17 moles
Explanation:
In the elements of the periodic table, the atomic mass = molar mass. <u>Ex:</u> Atomic mass of Carbon is 12.01 amu which means molar mass of Carbon is also 12.01g/mol.
In order to find the # of moles in a 12 g sample of NiC-12, we will need to multiply the number of each atom by its molar mass and then add the masses of both Nickel and C-12 found in the periodic table:
- Molar Mass of Ni (Nickel): 58.69 g/mol
- Molar Mass of C (Carbon): 12.01 g/mol
Since there's just one atom of both Carbon and Nickel, we just add up the masses to find the molar mass of the whole compound of NiC-12.
- 58.69 g/mol of Nickel + 12.01 g/mol of Carbon = 70.7 g/mol of NiC-12
There's 12g of NiC-12, which is less than the molar mass of NiC-12, so the number of moles should be less than 1. In order to find the # of moles in NiC-12, we need to do some dimensional analysis:
- 12g NiC-12 (1 mol of NiC-12/70.7g NiC-12) = 0.17 mol of NiC-12
- The grams cancel, leaving us with moles of NiC-12, so the answer is 0.17 moles of NiC-12 in a 12 g sample.
<em>P.S. C-12 or C12 just means that the Carbon atom has an atomic mass of 12amu and a molar mass of 12g/mol, or just regular carbon.</em>
Rutherford, Geiger and Marsden's experiment proved that every atom has a nucleus and that this nucleus is of positive charge and contains the most of the mass of the atom. 0.005% of the volume occupied by the electrons is the volume of the nucleus.
The order of placement of the elemnts on the modern Periodic Table is determinated by:
1)atomic number (Z=number of protons).
