Answer: a very large number of objects
Explanation: Mole is the amount of objects and it has the usually Avogadro number of atoms, molecules, ions, etc in chemistry
Answer:
2. The metal would lose one electrons and the non metal would gain one electrons
Explanation:
An atom of a certain element reacts with the atoms of other elements in order to fullfill its outermost shell (called valence shell).
We notice the following:
- The elements in Group 1 (which are metals) have only 1 electron in their valence shell
- The elements in Group 17 (which are non-metals) have 1 vacancy (lack of electron) in their valence shell
This means that in order for both an atom of group 1 and an atom of group 17 to fullfill the valence shell, they have to:
- The atom in group 1 has to give away its only electron of the valence shell
- The atom in group 17 has to gain one electron in order to fullfill the shell
Therefore, the correct option is
2. The metal would lose one electrons and the non metal would gain one electrons
Answer: Edge length of the unit cell = 628pm
Explanation: For a body centred cubic structured system, the relationship between the edge length of the unit cell and radius of the atoms in the structure is
Edge length of Unit cell (a) = (4R)/(√3)
R = 272pm = (272 × (10^-12))m = (2.72 × (10^-10))m
a = (4 × (2.72 × (10^-10)))/(√3)
a = (6.28157 × (10^-10))m = 628pm
Answer:
7.16x10⁻⁸M = [Ag+]
Explanation:
Using the equation:
E(Cell) =E⁰ - 0.0592/2 • log ([Cu2+]/[Ag+]²)
<em>Where E</em>⁰<em>= 0.4249V</em>
<em>E(Cell) = -(-0.0019V) -Measured value-</em>
<em>[Cu2+] = 1M</em>
<em />
Replacing:
0.0019V = 0.4249V - 0.0592/2 • log (1M/[Ag+]²)
-0.423V = - 0.0296 • log (1M/[Ag+]²)
14.29 = log (1M/[Ag+]²)
1.95x10¹⁴ = 1M / [Ag+]²
[Ag+]² = 5.12x10⁻¹⁵M
7.16x10⁻⁸M = [Ag+]
Use the atomic mass of potassium, k, 39.1 g/mol, and the formula n = mass / atomic-mass.
Where n is the number of moles.
n = 250.0 g / 39.1 g/mol = 6.3939 mol.
Now multiply by Avogadro number to find the number of atoms:
6.3939 mol * 6.02*1023 atoms/mol = 38.49 * 10^23 atoms = 3.849 * 10^24.
Answer: 3.85*10^24
