D = m / V
It even gives you the density of gold in the problem. Major hint. Once you know the volume (using V = m / D) then you can calculate the height (thickness) from the equation...
V = L x W x H
Volume = Length x Width x Height
start by converting 200.0 mg into grams
1000 mg = 1 g
200. mg x (1 g / 10^3 mg) = 0.200 g
V = m / D
V = 0.200 g / (19.32 g/cm^3)
V = 0.01035 cm^3
Convert 2.4 ft and 1 ft to cm
2.4 ft x (12 in / 1 ft) x (2.54 cm / 1 in) = 73.15 cm
1 ft = 30.48 cm
Compute the height (thickness)
V = LxWxH
H = V / LW = 0.01035 cm^3 / 73.15 cm / 30.48 cm
H = 4.64 x 10^-6 cm
Convert to nanometers
4.64 x 10^-6 cm x (1 m / 100 cm) x (10^9 nm / 1 m) = 46.4 nm
Knowing the atomic radius of gold, I might have asked my students for the minimum number of gold atoms in this thickness of gold. This would assume that the gold atoms are all in a row. This would give the minimum number of gold atoms.
Atomic radius gold = 174 pm
Diameter = 348 pm
46.4 nm x (1 m / 10^9 nm) x (10^12 pm / 1 m) x (1 Au atom / 248 pm) = 133 atoms of gold
Answer:
Old and inefficient mining smokestacks contaminate the soils around abandoned mine sites.
Explanation:
A smokestack, is a very tall channel commonly used in many instances to release gases produced by combustion processes directly into the air. These high towers are aimed at dispersing the gaseous pollutants over a wider area thereby minimizing their impact.
Old and inefficient smokestack do not contaminate the soil since they are very high towers that discharge gases directly into the atmosphere. Hence they are not part of the sources of soil contamination in abandoned mines.
The uncertainty principle is one of the most famous (and probably misunderstood) ideas in physics. It tells us that there is a fuzziness in nature, a fundamental limit to what we can know about the behaviour of quantum particles and, therefore, the smallest scales of nature. Of these scales, the most we can hope for is to calculate probabilities for where things are and how they will behave. Unlike Isaac Newton's clockwork universe, where everything follows clear-cut laws on how to move and prediction is easy if you know the starting conditions, the uncertainty principle enshrines a level of fuzziness into quantum theory.
This Should help you
It is <u>true</u> that ionic compounds are formed from atoms that have opposite charges.
<h3>What are ionic compounds?</h3>
Ionic compounds are chemical compounds made up of ions held together by electrostatic forces termed ionic bonding.
The ionic compound formed is neutrally charged but consists of positively charged ions called cations and negatively charged ions called anions.
For example, the sodium ions attract chloride ions and the chloride ion attracts sodium ions. The result is the formation of an ionic compound with cation Na+ and anion Cl– ions.
Therefore, it is true that an ionic compound is made up of positive and negative ions.
Learn more about ionic compound at: brainly.com/question/9167977
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• Bubbles of a colourless, odourless gas are evolved
• The solution turns red litmus blue
Ca + 2H_2O→ Ca(OH)_2 + H_2
