They are made up of particles that are arranged in a repeating pattern.
The SI base units and their physical quantities are the metre for measurement of length, the kilogram for mass, the second for time, the ampere for electric current, the kelvin for temperature, the candela for luminous intensity, and the mole for amount of substance.
Answer: -
sigma factor mRNA RpoH sigma H sigma 32
Explanation: -
It is the heat shock sigma factor which activates due to heat. The factor will bind with to the polymerase-core-enzyme. After this other heat ans shock proteins are expressed.
This thus enable the cell to survive higher temperatures. Some of the enzymes that are expressed upon activation are chaperones, proteases and DNA-repair enzymes
Answer: The calcium and magnesium metal samples had undergone a chemical reaction (oxidation) with the oxygen present in the air around the shelf to form oxides which caused them to lose their metallic luster overtime. This process is known as tarnishing.
Aluminium also undergoes this process but at a slower rate due to its lower reactivity compared with calcium or magnesium.
Explanation:
Calcium and magnesium belong to the group 2 of the periodic table of metals,generally called alkaline earth metals. They are very reactive and on exposure to air, they react with the oxygen present in air to form <em>coatings/films</em> of calcium oxide and magnesium oxide respectively over the metals. This causes the metals to lose their metallic shine or luster overtime.
Aluminium also undergoes this process generally known as <em>tarnishing</em> forming aluminium oxide but at a slower rate when compared to calcium or magnesium due to their being more reactive than aluminium is.
