Elements are ionized because they aspire to be stable. The most stable form are the ones with full octet of electrons, the noble gases which consist of the last column in the periodic table. The rest of the elements either accept or readily donate electrons to conform to the electronic configuration that is the same with the nearest noble gas.
1. Potassium's nearest noble gas is Ar which is one electron fewer. So, when ionized, it donates 1 electron. Hence, K⁺.
2. The nearest noble gas for fluorine is Neon which is 1 electron more. Hence, it has to accept one more electron. Hence, F⁻.
The molarity of a solution equals to the mole number of the solute/the volume of the solution. For NH4Br, we know that the mole mass is 98. So the molarity is (14/98) mol /0.15 L=0.95 mol/L.
Answer:
8.0 moles
Explanation:
Since the acid is monoprotic, 1 mole of the acid will be required to stochiometrically react with 1 mole of NaOH.
Using the formula: 
Concentration of acid = ?
Volume of acid = 10 mL
Concentration of base = 1.0 M
Volume of base = 40 mL
mole of acid = 1
mole of base = 1
Substitute into the equation:
Concentration of acid = 40/10 = 4.0 M
To determine the number of moles of acid present in 2.0 liters of the unknown solution:
Number of moles = Molarity x volume
molarity = 4.0 M
Volume = 2.0 Liters
Hence,
Number of moles = 4.0 x 2.0 = 8 moles
Answer:
The glow stick in hot water will be brighter
Explanation:
The glow stick in hot water will be brighter than the glow stick in cold water because the heat from the hot water will cause the molecules in the glow stick to move faster. The faster the molecules move in the glow stick, the sooner and brighter the reaction will be. The cold water will cause molecules to move slowly and it will take longer for the reaction to occur, which will also make it less bright.
