Answer:
Chemical change
Explanation:
The rusting of iron/a nail is a chemical change
Iron (Fe) and Oxygen (O) combine to create the compound Iron Oxide (Fe2O3), which is rust.
Answer:
The Symbols of elements is given by :
IUPAC : International Union Of Pure and Applied Chemistry .
Its is the Universally recognuised organisation which works on Chemical nomenclature and terminology.
Explanation:
According to IUPAC the elements are named according to mythological concept of country ,mineral , place , property and scientist.
Ex:Copper name comes from the old english word Cyprus.
Rules of Naming elements :
1. The first Alphabet of the element is always Capital.Example:-
Sodium : Na not ''na'
2. The second alphabet is always small .Example
Sodium : Na not ''nA' or NA
3.For most of the elements ,The symbol of the element comes from the <u>first two words.</u>
Example : Hydrogen : H
Helium : He
Copper : Cu
Rules for naming elements having mass> 100
1. The names are derived directly from the atomic number .
Ex : 0 = nil 1= un 2=bi 3=tri
2. The name always ends with ''ium''
For example :
102 = Unnilbium
Answer:
The air above land also warms faster than air above the sea. Cooler higher pressure air above the ocean moves toward warmer lower pressue air above land.
Answer: -
The chemical formula of Antimony(III) sulfide = Sb₂S₃
Mass of Sb produced = 175.6 g
Molar mass of Sb = 121.76 g /mol
Number of moles of Sb = 175.6g / (121.76 g/mol)
= 1.44 mol
The balanced chemical equation for this reaction is
Sb₂S₃ + 3 Fe → 2 Sb + 3 FeS
From the chemical equation we see
2 mol of Sb is produced from 1 mol of Sb₂S₃
1.44 mol of Sb is produced from 
= 0.72 mol of Sb₂S₃
Molar mass of Sb₂S₃ = 2 x 121.76 + 32.06 x 3
= 339.7 g / mol
Mass of Sb₂S₃ = 0.72 mol x 339.7 g/ mol
= 244.58 g
= 244.6 g rounded off to 4 significant figures.
