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Questions in chemistry

[Done] 1. Ag (silver) tarnishes. Is this a physical or chemical property? 2. An apple is cut. Is this a physical or chemical property?

[Done] How is an average mass different from a weighted average mass?

[Done] Why can't color alone be used to identify most minerals?

[Done] Could a mixture be made up of only elements and no compounds?

[Done] As the elements in Period 3 are considered in order of increasing atomic number, there is a general decrease in: - atomic radius There is generally an increase in: - atomic mass - electronegativity - first ionization energy

[Done] Why do copper ions go to the negative electrode?

[Done] A. Thermal decomposition of 2.765 g NaHCO\(_3\) yields 1.234 g of solid Na\(_2\)CO\(_3\). Calculate the theoretical yield and percent yield of Na\(_2\)CO\(_3\). B. Thermal decomposition of 2.968 g of a mixture containing NaHCO\(_3\) lost 0.453 g. Calculate the percentage of NaHCO\(_3\) in this unknown mixture.

[Done] Sequence the following types of waves from lowest frequency to highest frequency: - Radio waves - Infrared rays - Green light - Ultraviolet rays - Gamma rays

[Done] Which layer of the Earth can only be studied by indirect means?

[Done] Suggest two reasons why copper should not be disposed of in landfill sites.