The first rule is to use four digits in atomic weights and consider the calculated formula or molar mass as given with four significant digits. This rule is appropriate for beginners but has some disadvantages.
The second rule is to use all digits in the recommended atomic weights and to estimate the accuracy of the result from the number of decimal places or significant digits in these.
The third rule is to use all digits in the recommended atomic weights and to calculate the absolute maximum uncertainty of the result from the recommended uncertainties of the atomic weights. The uncertainty is rounded up to one (two) significant digit(s), and the formula or molar mass is rounded to the same absolute accuracy as the rounded uncertainty.
<h2>Hardness, lustre, and colour.</h2>
Explanation:
These Rocks shown in photographs are made of different types of minerals which have properties as follows:
●The color of the rock is grey, brown and yellow after it is ground into a powder its color is streak.
● The lustre of the rock tells how shiny the rocks are.
● Other properties include hardness, texture, shape, and size.
Answer:
C10H22
Explanation:
Molecular Solids comprises of a Vander waal's force of attraction between the molecule. These forces are very weak when compared to ionic and covalent bond.
In Carbon, Carbon is not a molecule but an atom. One of it unique characteristics is that it forms bonds with other carbon atoms. This property is know as catenation. The bond between these carbon atoms is know as covalent bond.
Graphite is an allotrope of carbon. It exists as black , slippery, hexagonal crystals.The carbon atoms in graphite forms flat layers and are joined together by strong covalent bonds. Graphite can be used as lubricant in engines.
Gold (Au) is an element on the periodic table with atomic number 79 and a mass number 197. It exists as a metal. Most times Gold forms hydrogen bonds.
C10H22 is known as decane. It is the tenth compound formed in the series of alkane family( an organic unsaturated carbon chain family). Alkanes are aliphatic hydrocarbons. The forces of attraction between the alkane family are weak.In decane , their exists Vander waal's force which makes Decane C10H22 a Molecular Solid.
The reaction of hydrogen gas (H2) with oxygen gas (O2) is a COMBINATION or SYNTHESIS reaction, because multiple substances combine to form fewer substances. Here, the two gases form one substance, water (H2O):
2H2 + O2 -- > 2H2O
