There are a couple of ways todetermine if a reaction is exothermic or endothermic. Endothermic meaning that heat is added to the reaction to make the reactants interact and exothermic meaning heat is released during the reaction between the two reactants.
In endothermic reactions you can find a triangle above the arrow.
N = cv
1.46 = 0.1 x v
v = 1.46/0.1
v = 14.6 (litres if it’s moles per litre)
Answer:
So for your question, the Periodic Table tells us that sodium has an Atomic Number of 11, so there are 11 protons and 11 electrons. The Periodic Table tells us that sodium has an Atomic Mass of ≈23. So there are 23 - 11 = 12 neutrons.
Explanation:
Positive
And Negative for oxygen.
Use the atomic mass of potassium, k, 39.1 g/mol, and the formula n = mass / atomic-mass.
Where n is the number of moles.
n = 250.0 g / 39.1 g/mol = 6.3939 mol.
Now multiply by Avogadro number to find the number of atoms:
6.3939 mol * 6.02*1023 atoms/mol = 38.49 * 10^23 atoms = 3.849 * 10^24.
Answer: 3.85*10^24