How many moles of silver atoms are in 1.8x10^20 atoms of silver? a. 3.0x10^-4 b. 3.3x10^-3 c. 3.0x10^2 d. 1.1x10^44 #19 in photo add work and explanation

Taking into account the definition of avogadro's number, the correct answer is option A. 3×10⁻⁴ moles of silver are 1.8×10²⁰ atoms of silver.

Avogadro's Number or Avogadro's Constant is called the number of particles that make up a substance (usually atoms or molecules) and that can be found in the amount of one mole of said substance. Its value is 6.023×10²³ particles per mole. Avogadro's number applies to any substance.

Then you can apply the following rule of three: if 6.023×10²³ atoms are contained in 1 mole of silver, then 1.8×10²⁰ atoms are contained in how many moles of silver?

amount of moles of silver= (1.8×10²⁰ atoms × 1 mole)÷ 6.023×10²³ atoms

amount of moles of silver≅ 3×10⁻⁴ moles

Finally, the correct answer is option A. 3×10⁻⁴ moles of silver are 1.8×10²⁰ atoms of silver.

Learn more about Avogadro's Number:

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3.0 x 10⁻⁴ moles

Explanation:

Given parameters:

Amount of Ag atoms = 1.8 x 10²⁰ atoms

Unknown:

Number of moles of Ag atoms

Solution:

From mole concept, we know that a mole of a substance contains Avogadros number of particles.

The Avogadro's number of particles is 6.02 x 10²³.

Now:

Number of moles

= number of particles/6.02 x 10²³

Therefore:

Number of moles= 1.8 x 10²⁰ / 6.02 x 10²³

Number of moles = 0.3 x 10⁻³ moles

= 3.0 x 10⁻⁴ moles

the best answer is d because the strong cohesion is caused by the ability of water molecules to undergo hydrogen bonding.

a is incorrect because when water solidifies, it becomes   ice, which expands and occupies a bigger volume for the same mass of water in its liquid state.

b is incorrect because water has high surface tension. besides bonding to itself it hydrogen bonds to other molecules at the top decreasing possibility for breaking of attractive forces.

c is incorrect because the water molecule has oxygen which is highly electronegative and so pulls the electron pair towards itself creating a dipole moment, making the molecule polar.

e is incorrect because water has strong adhesion, ability to stick to other molecules such as glass because of this molecules having stronger hydrogen bonding than water.