1 is D - double-replacements do not make solid metals
2 is A - to have complete combustion the original compound must ONLY have C, H and O
3 is B - the elemental Mg replaces the H in the HCl
Increasing temperatures in a reaction increases the kinetic energy of the reactant molecules. This causes them to move fast and hence collide with a higher frequency. The higher the rate of collision between the molecules, the faster the reaction.
Answer:
5.12x10¹¹ millimeters
Explanation:
Milli is a prefix used in science and engineering to decribe the number as the exponent x10⁻³. In the prefix kilo, the number is at the exponent x10³.
5.12x10⁵ kilometers are:
5.12x10⁵ kilometers * (1000m / 1km) = 5.12x10⁸ meters
5.12x10² meters * (1m / 1000millimeters) = 5.12x10¹¹ millimeters
Explanation :
As we know that Mendeleev arranged the elements in horizontal rows and vertical columns of a table in order of their increasing relative atomic weights.
He placed the elements with similar nature in the same group.
According to the question, the atomic weight of iodine is less than the atomic weight of tellurium. So according to this, iodine should be placed before tellurium in Mendeleev's tables. But Mendeleev placed iodine after tellurium in his original periodic table.
However, iodine has similar chemical properties to chlorine and bromine. So, in order to make iodine queue up with chlorine and bromine in his periodic table, Mendeleev exchanged the positions of iodine and tellurium.
As we know that the positions of iodine and tellurium were reversed in Mendeleev's table because iodine has one naturally occurring isotope that is iodine-127 and tellurium isotopes are tellurium-128 and tellurium-130.
Due to high relative abundance of tellurium isotopes gives tellurium the greater relative atomic mass.
An accepted and universally true explanation of observed facts is a law.
