Monday, February 21, 2011

Martian Elements

NASA's Mars Science Laboratory rover, Curiosity, is due to be launched between November 25th and December 18th 2011 and should land on Mars in August 2012. Curiosity will carry a next generation, onboard "chemical element reader" to measure the chemical ingredients in Martian rocks and soil.

The Alpha Particle X-Ray Spectrometer (APXS) instrument uses alpha particles and X-rays to bombard a target, causing the target to give off its own characteristic alpha particles and X-ray radiation. This radiation is than read by an X-ray detector which reveals which elements are present in the sample, and how much of the element is present.
Scientists will use information from APXS to figure out the present and past environmental conditions that are preserved in the rocks and soils.

Currently, scientists believe that the most abundant elements on Mars are silicon and oxygen, then iron, magnesium, aluminium, calcium, and potassium, which are the elements that make up igneous rocks, the minerals that crystallize from magma. The characteristic red colour of Mars is due to the presence of iron oxides. Titanium, chromium, manganese, sulfur, phosphorus, sodium and chlorine are also present in much smaller amounts.
Hydrogen is present in water. In 2008, NASA announced that the Phoenix lander had confirmed the presence of water in the form of ice on the Martian polar ice caps.
Carbon occurs as carbon dioxide in the atmosphere, and as dry ice at the Martian poles, while some carbon is stored as carbonates. Phoenix Mars lander in 2007 found alkaline soil containing calcium carbonate, and in 2010, Mars Exploration Rover Spirit identified deposits of magnesium-iron carbonate.
About 95% of the Martian atmosphere is carbon dioxide. Nitrogen gas makes up 2.7% of the Martian atmosphere, then smaller amounts of argon, oxygen, carbon monoxide, water vapor, and nitric oxide. Tracer amounts of neon, krypton, formaldehyde, xenon, ozone and methane have also been detected.

NASA/Jet Propulsion Laboratory (2011, February 20). Advanced NASA instrument gets close-up on Mars rocks. ScienceDaily. Retrieved February 22, 2011, from­ /releases/2011/02/110220204711.htm

Further Reading
Elements and Compounds
Metals and Non-metals
Periodic Table

Study Questions:
  1. Draw up a table with two headings; element name and chemical symbol. Enter the name and symbol of each element named in the article above into the table.
  2. Draw up a table with two headings, elements in Martian rocks, and, elements in Martian atmosphere. Enter each element mentioned in the article above into the table in the appropriate column.
  3. Draw up a table with three headings, metals, non-metals and semi-metals (metalloids). Enter each of the elements named in the article above into the table in the correct column.
  4. Use a Periodic Table to find the atomic number of each element named in the article above.
  5. Name three compounds mentioned in the article above and write the chemical formula for each one.
  6. Name each of the Group VIII (Noble Gases) mentioned in the article and give the chemical symbol for each one.
  7. Name the organic (carbon) compounds mentioned in the article and give the molecular formula for each one.
  8. What is an alpha particle?

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