It's where chemical elements are organized based on atomic weight. Also, like/similar physical and chemical properties in each interval of 7 elements.
It was a silly reason it was rejected. It was rejected because it's octaves were too similar to those in music.
I hope this helps!
Answer: The correct option is C ( is very hard and burns cleanly).
Explanation:
COAL is a form of rock that is made up of mostly carbon amongst other elements which includes sulphur, nitrogen, hydrogen and oxygen. There are different types of coal which include:
--> anthracite ( 90% carbon)
--> bituminous coal ( 70-90% carbon)
--> lignite ( 60- 70% carbon) and
--> peat (60 % carbon).
Anthracite is the type of coal that contains the highest carbon content ( 90% carbon). This makes it very hard and is often a times referred to as HARD COAL. Anthracite is a higher quality coal for domestic and open fire heating. This is because it contains less impurities than other type of coal and thereby making it to BURN CLEANLY avoiding atmospheric pollution.
Rubidium or strontium have larger a larger atomic radius since the further left on the periodic table you go, the larger the sizes of the atoms are. This trend can be explained through effective nuclear charge which explains how the further left and down you go, the less the atoms nucleus is able to pull in the electrons around it.<span />
Answer:
cuerpo flota o se hunde es su densidad con respecto a la del líquido en que se sumerge. En cambio, una nuez (densidad = 0.5) flotara en ambos líquidos mientras que una piedra (densidad = 2) se hundirá.
Explanation:
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