Purchase Solution

# Density and Melting Point

Not what you're looking for?

Questions on density:
1. Using the table below determine any trends of density that might be related to the periodic table.
Substance Density (g/L) Substance Density (g/L)
H2 0.0899 O2 1.429
He 0.1785 N2 1.2506
Ne 0.9 Cl2 3.214
Ar 1.7825 Kr 3.75
F2 1.696 Xe 5.9

2. In the early days of the periodic table, the 1870s, both silicon and tin were known elements, but germanium was unknown. Using these trends and the densities of silicon and tin that you just obtained, estimate the density of germanium?

3. Melting Point
Halogen Melting point
F2 54 K
Cl2 172 K
Br2 266 K
I2 387 K

a. Graph the data above, put the melting point on the y-axis and atomic number on the x-axis

b. What trends if any do you notice from the data regarding melting point and the periodic table?

c. What is the predicted melting point of astatine? How did you determine the melting point? (Hint - use your graph)

##### Solution Summary

Density and melting points are provided for substances. The early periodic table is provided.

##### Solution Preview

1. The trend of density in the periodic table can be determined by looking at the atomic numbers - the higher the atomic number, the denser the atom.Among gaseous and liquid nonmetals, as atomic number increases, London dispersion forces increase with the number of electrons, resulting in higher polarity and intermolecular attraction. Therefore, density generally increases as atomic number increases.

The majority of metals have higher densities than the majority of nonmetals. The ...

Solution provided by:
• BSc (Hons),
• MSc,
• PhD,
###### Recent Feedback
• "Thankyou for the feedback. I have a few question though; With the first statistic about cost below... “According to Sigma-Aldrich catalog, cost of 1L octane is AUD \$ 392.00, whereas the cost of 1L ethanol is AUD \$196.00. Moreover, if ethanol is obtained from sugar industry as a by-product, it may cost even less. Source of oxygen is ambient atmosphere, so it costs nothing. So ethanol is much cheaper than petrol, in fact it is half-priced: AUD \$ (392-196) = \$ 196.” I didn't think it made sense because the cost of petrol per litre is normally a dollar something or even less than a dollar not a couple of hundred of dollars. For example, a statistic that I found in america was: "U.S. ethanol production costs are about \$1.20 per gallon of ethanol, or \$1.82 per gallon on a gasoline-equivalent basis." However, I was wondering whether you could find an Australian statistic. Also, you mentioned that H20 is not a greenhouse gas. However, in the combustion equations it is actually carbon dioxide and water vapour which are produced and they are both greenhouse gases. Finally, how do I calculate the energy efficiency of ethanol and petrol? "
• "Thank you!"
• "Didnt really answer my questions but gave me a start at least."
• "Once again this is tremendous help I can't thank you enough for not only working the problem but explaining in detail how and why!! KR"
• "Awesome thank you so much for the help!!!"

##### Organic Chemistry Naming: Alkanes

This is a quiz which is designed to assist students with learning the nomenclature used to identify organic compounds. This quiz focuses on the organic compounds called Alkanes.

##### General Chemistry - Classification of Matter

This test will assess your knowledge on the classification of matter which includes elements, compounds and mixtures.

##### Match Elements with their Symbols

Elements are provided: choose the matching one- or two-letter symbol for each element.

##### Functional groups in Organic Chemistry

You will be tested on the names of functional groups in Organic Chemistry. It is very important to know the functional groups to understand Organic reactions.