Silicon has 14 protons Potassium has 19 electrons The neutrons are equal to the mass number minus the atomic number. Or the big number minus the small number on the periodic table. hydrogen 1 does not have a neutron.
iron =56 -26 for 30 neutrons in the nucleus
Chlorine 17 protons and 17 electrons. 18 or 19 neutrons on average.
You would do 82.75 divided by 125 cm3 and get 0.6620 g/cm3 because to find density you mist divide mass and volume and grams is always mass and cm3 or mL is always volume. hope i helped!
Try putting this in biology category not chemistry so more ppl can help :)
Answer:
Rb: [Kr] 5s
Step-by-step explanation:
Rb is element 37, the first element in Period 5.
It has one valence electron, so its valence electron configuration is 5s.
The noble gas configuration uses the symbol of the previous noble gas as a shortcut for the electron configurations of the inner electrons.
The preceding noble gas is Kr, so the electron configuration is Rb: [Kr] 5s.
The answer is B
Vaporization
