Explanation:
Scandium has atomic number of 21. This means that in it's neutral state its going to have 21 electrons.
a) The full electronic configuration is given as;
1s2 2s2 2p6 3s2 3p6 3d1 4s2
The final electron is placed in the d orbital. The shell is 3d
(b) When scandium has a charge if +1, it has lost an electron. The total number of electrons would now be 21-1 = 20
The electronic configuration would be given as;
1s2 2s2 2p6 3s2 3p6 4s2
The electron in the 3d orbital would be removed.
Endothermic reactions. These are reactionsthat take in energy from the surroundings. The energy is usually transferred as heat energy, causing the reaction mixture and its surroundings to get colder
The boiling point is the temperature at which the vapour pressure of the solution or solvent becuase equal to the ambient pressure, and bubbles of vapour from directly in the liquid. The normal boiling point is specified when the ambient pressure ( And also thvapour pressure of the boiling liquid) is One atmosphere. Ans so where strong intermolecular forces of attraction operate for instance in Hydrogen-Bonded liquids, boiling point should be elevated. More energy has to be put into the system to disrupt the intermolecular force. And the best indicator or intermolecular or inter-particle force is boiling point.
Answer: 2) 0.21 mole H2O
3) 0.50 mole K2O
4) 123 g Ca( NO3)2
Explanation: solution attached.
For number 2 to find the number of moles of H2O just divide the given in molecules with the Avogadro's number.
For 3 convert grams of K2O to moles by using 1 mole of K2O is equal to the molar mass of K2O
For number 4 moles to grams. Same process with number 3
