<u>Answer:</u> The mass of arsenic found in the sample is 0.25 mg
<u>Explanation:</u>
ppm is the amount of solute (in milligrams) present in kilogram of a solvent. It is also known as parts-per million.
To calculate the ppm of oxygen in sea water, we use the equation:

Both the masses are in grams.
We are given:
Concentration of arsenic = 5 ppm
Mass of sample = 50 g
Putting values in above equation, we get:

<u>Conversion factor used:</u> 1 g = 1000 mg
Hence, the mass of arsenic found in the sample is 0.25 mg
Answer: Zinc nitride (Zn3N2) is an inorganic compound of zinc and nitrogen, usually obtained as (blue)grey crystals. It is a semiconductor. In pure form, it has the anti-bixbyite structure.
Chemical formula: Zn3N2
Space group: Ia-3, No. 206
EC Number: 215-207-3
Appearance: blue-gray cubic crystals
Explanation:
Answer:
The Avogadro's number is 
Explanation:
From the question we are told that
The edge length is 
The density of the metal is 
The molar mass of Ba is 
Generally the volume of a unit cell is

substituting value
![V = [5.02 *10^{-10}]^3](https://tex.z-dn.net/?f=V%20%3D%20%20%5B5.02%20%2A10%5E%7B-10%7D%5D%5E3)
From the question we are told that 68% of the unit cell is occupied by Ba atoms and that the structure is a metal which implies that the crystalline structure will be (BCC),
The volume of barium atom is

substituting value


The Molar mass of barium is mathematically represented as

Where
is the Avogadro's number
So

substituting value


Answer:
1.23x10^-6 mole
Explanation:
A clear understanding of Avogadro's hypothesis proved that 1mole of any substance contains 6.02x10^23 atoms. This indicates that 1mole of Ag contains 6.02x10^23 atoms.
Now, 1f 1mole of Ag contains 6.02x10^23 atoms, then Xmol of Ag will contain 7.41x10^17 atoms i.e
Xmol of Ag = 7.41x10^17/6.02x10^23 = 1.23x10^-6 mole
Answer:
B
Explanation:
B, H2O + Na The elements toward the bottom left corner of the periodic table are the metals that are the most active in the sense of being the most reactive. Lithium, sodium, and potassium all react with water,