Answer:
Explanation:
The kPa-kilopascal is the unit of pressure. It was named after Blaise Pascal, a mathematician and physicist.
The kPa is 1000Pa. Kilo stands for 1000. Now what is a pascal?
A pascal is the amount of force(Newton) exerted per unit area.
1Pa = 1Nm⁻²
At the standard atmospheric level, the pressure is 101.325 x 10³ Nm⁻² i.e the atmosphere exerts a pressure of 101.325 x 10³N in an area of a body.
This unit is used to calculate pressure. It can be converted to other units.
Question 1. What one factor identifies an atom as a specific element? Answer: the number of protons. Remember that the atoms of a same element have the same number of protons, and the atoms of different elements cannot have the same number of protons. That permits to order the elements according to the atomic number (number of protons) in the periodic table. Question 2.An atom of fluorine has an atomic number of 9 and an atomic mass of 19. The atom contains Answer: 9 protons, 9 electrons, and 10 neutrons : because the atomic number is the number of protons, the number of electrons must be equal to the number of protons (because the atom is neutral), and the mass number is the number or protons plus the number of neutrons: 9 protons + 10 neutrons = 19 mass number (atomic mass). Question 33.Experiments with cathode ray tubes led to a new model of the atom, sometimes called the \"plum pudding\" model, because of the discovery of the <span>. Answer. electron ... when electron was discovered JJ Thompson proposed the plum pudding model, in which the atom was a solid positively charged sphere with electrons distributed inside it.</span>
Answer:
0.266 moles of Na⁺
Explanation:
First step we dissociate the salt:
Na₃AsO₄ → 3Na⁺ + AsO₄⁻³
From 1 mol of sodium arsenate, we must have 3 moles of sodium cation and 1 mol of arsenate.
We determine the moles of salt:
18.4 g . 1 mol/ 207.89 g = 0.0885 moles of salt.
We apply the followring rule of three:
1 mol of salt has 3 moles of Na⁺
0.0885 moles of salt may have (0.0885 . 3) / 1 = 0.266 moles of Na⁺
