<span>It is the valence orbit that controls the electrical properties of the atom. The valence electron is referred to as a "free electron.' Valence electrons have the highest energy of all electrons in an atom; they are also the most reactive, meaning they are usually the electrons involved in bonding. When silicon atoms combine to form a solid, they arrange themselves into an orderly pattern called a crystal.</span>
The atom has only one isotope which means 100 % of same atom is present in nature. The atomic mass of an element is the number of times an atom of that element is heavier than an atom of carbon taken as 12. Mass of one atom of that isotope is 9.123 ✕ 10⁻²³ g, so mass of one mole of atom that is Avogadro's number of atom is 6.023 X 10²³ X 9.123 X 10⁻²³ g=54.94 g = 55 g (approximate).
So, the atom having atomic mass 55 will be Cesium (Cs). Only one isotope of Cesium is stable in nature.
Volume = Mass / Density
Volume = 540g / 2.70 g/ml
Volume = 200 ml
Answer:
0.12 mol KCl
Explanation:
2 KClO3 (s) 2 KCl (s) + 3 O2 (g)
15 g x mol
x g KCl = 15 g KClO3 x[ (1 mol KClO3)/ (122.5 g KClO3) ] x [(2 mol KCl)/ (2 mol KClO3)]
x g KCl = 0.12 mol KCl
When we can get the Kinetic energy from this formula KE= 1/2 M V^2and we can get the potential energy from this formula PE = M g H
we can set that the kinetic energy at the bottom of the fall equals the potential energy at the top so, KE = PE
1/2 MV^2 = M g H
1/2 V^2 = g H
when V is the velocity, g is an acceleration of gravitational force (9.8 m^2/s) and H is the height of the fall (8 m).
∴ v^2 = 2 * 9.8 * 8 = 156.8
∴ v= √156.8 = 12.5 m/s
