The ore contains 55.4% calcium phosphate (related to the mineral apatite) so the amount of Ca3(PO4)2 is 55.4%x=1000g so x=1000/0.554= 1.805kg. Now for the % of P in this amount of calcium phosphate, use all the masses of the elements in Ca3PO4= Ca=40.078 x 3= 120.23 and (PO4)2= (30.974+64)2=189.95 (NB oxygen is 16 mass x 4 =64) so the total mass is 310.2 and we have 61.95 of P (Pmass x 2) so 61.95/3102.= 0.19 or 19% P. So of the 1.805 x 0.19= 0.34kg of phosphorus.
Answer : Option C) Non metal.
Explanation : A non metal is the one which does has poor thermal conductivity, poor electrical conductivity, are usually brittle solids which are not malleable or ductile, they have little or no metallic luster at all, and they gain electrons easily.
These are the properties which are seen in a non metal.
Answer:
Tau ceti
Explanation:
it's the closest next to the sun
Chemical reactions can be broadly classified into two categories from the context of heat requirement. These include; endothermic and exothermic reactions.
Endothermic reactions proceed with the absorption of heat while exothermic reactions are accompanied by the evolution of heat.
1) Oxidation of iron involves reaction of elemental iron with oxygen to form iron oxide (rust). This is essentially a corrosion reaction in which the metallic bonds in Fe are broken and new bonds between Fe and O are formed, This is an exothermic reaction
4Fe + 3O2 → 2Fe2O3
Ans D)
2) The process of condensation i.e. phase change liquid to solid (or gas to liquid) involves release of heat to the surroundings, hence it will be an exothermic reaction.
Ans B)
3) Specific heat is the amount of heat required to raise the temperature of 1 g of a substance by a 1 C. Typically, liquids and gases are used as coolants. For a coolant to be efficient, it must have a high specific heat.
Ans B)
