Answer:
(C) Energy is released when the electron is ejected from the atom.
Explanation:
In the Bohr model of the atom, electrons are arranged in energy levels. The electrons in the lowest energy levels are nearest to the nucleus. An electron may move from a lower to a higher energy level by absorbing energy that is equal to the difference between the energies of the higher and lower energy level.
The potential energy of all electrons inside the atom have negative values and an electron which is infinitely far from the nucleus has an electrostatic potential energy of zero.
Energy is absorbed when an electron is removed from the atom (ionization). Hence the process is highly endothermic. Therefore it is false to say that "Energy is released when the electron is ejected from the atom."
THE KINETIC MOLECULAR THEORY STATES THAT ALL PARTICLES OF AN IDEAL GAS ARE IN CONSTANT MOTION AND EXHIBITS PERFECT ELASTIC COLLISIONS.
Explanation:
An ideal gas is an imaginary gas whose behavior perfectly fits all the assumptions of the kinetic-molecular theory. In reality, gases are not ideal, but are very close to being so under most everyday conditions.
The kinetic-molecular theory as it applies to gases has five basic assumptions.
- Gases consist of very large numbers of tiny spherical particles that are far apart from one another compared to their size.
- Gas particles are in constant rapid motion in random directions.
- Collisions between gas particles and between particles and the container walls are elastic collisions.
- The average kinetic energy of gas particles is dependent upon the temperature of the gas.
- There are no forces of attraction or repulsion between gas particles.
Answer:
The mass of 2,50 moles of NaCl is 146, 25 g.
Explanation:
First we calculate the mass of 1 mol of NaCl, starting from the atomic weights of Na and Cl obtained from the periodic table. Then we calculate the mass of 2.50 moles of compound, making a simple rule of three:
Weight NaCl= Weight Na + Weight Cl= 23 g+ 35,5 g= 58, 5 g/ mol
1 mol ------ 58, 5 g
2,5 mol---x= (2,5 mol x 58, 5 g)/ 1 mol = <u>146, 25 g</u>
Mass of KCl= 19.57 g
<h3>Further explanation</h3>
Given
12.6 g of Oxygen
Required
mass of KCl
Solution
Reaction
2KClO3 ⇒ 2KCl + 3O2
mol O2 :
= mass : MW
= 12.6 : 32 g/mol
= 0.39375
From the equation, mol KCl :
= 2/3 x mol O2
= 2/3 x 0.39375
=0.2625
Mass KCl :
= mol x MW
= 0.2625 x 74,5513 g/mol
= 19.57 g
