Answer:
CO32−
Explanation:
We have to consider the valencies of the polyatomic ions involved. Recall that it is only a polyatomic ion with a valency of -2 that can form a compound which requires two sodium ions.
When we look closely at the options, we will realize that among all the options, only CO32− has a valency of -2, hence it must be the required answer. In order to be double sure, we put down the ionic reaction equation as follows;
2Na^+(aq) + CO3^2-(aq) ---------> Na2CO3(aq)
Answer:
Based on the Modern Periodic table, there is an increase in the electropositivity of the atom down the group as well as increases across a period. On comparing the electropositivities of the mentioned oxides central atom, it is seen that Ca is most electropositive followed by Al, Si, C, P, and S is the least electropositive.
With the decrease in the electropositivity, there is an increase in the acidity of the oxides. Thus, the increasing order of the oxides from the least acidic to the most acidic is:
CaO > Al2O3 > SiO2 > CO2 > P2O5 > SO3. Hence, CaO is the least acidic and SO3 is the most acidic.
Answer:
Never smoke near a place where hydrogen is generated or being used. Remove all possible sources of flame and sparks. Hydrogen should only be generated and used in a well ventilated out door area. Precautions must be taken to remove all possibilities of fire or explosion.
Answer:
Detail is given below.
Explanation:
Similarities:
All are the forms of matter.
Solid, liquid and gases are made up of ions, atoms and molecules.
They have shape and volume.
Molecules in Liquid and solid are closer to each others.
Liquid and gases can flow very easily.
Liquid and solid both can not compressed very easily.
Differences:
Molecule of gases randomly move everywhere and occupy all available space but liquid and solid's molecules are not move as much easier as molecules of gases can.
The density of gases are very low as compared to the liquid and solid.
Gas molecules are at long distance from each other while in liquid and solid they are closer to each other.
The very weak inter molecular forces are present between gas molecules as compared to the liquid and solids.
Solids have definite volume and shape but liquid and gases acquire the shape of container.
In solids molecules are tightly pack and very close to each other while in liquid molecules are not tightly pack like in case of solid.
The densities of solids are also very high as compared to the liquid and gas.
There are very strong inter molecular forces are present between solid molecules.
J=75. Because he has already used 45 of his/her 120
