The atmosphere of earth is made of five main layers.
1) Troposphere : This is the lowest part of the atmosphere. Most of the air that makes up the atmosphere is present in this layer.
2) Stratosphere : This layer is present above troposphere and extends up to 50 km. It contains ozone layer which prevents the harmful ultraviolet rays from the sun from entering the lower troposphere
3) Mesosphere : The layer above stratosphere is known as mesosphere.
4) Thermosphere : The region lies above mesosphere.
5) Exosphere : The is the outermost region of the atmosphere.
From the above discussion we can see that the layer that lies between exosphere and mesosphere is Thermosphere
Answer:
Element X with atomic number 10 and atomic mass 21
Element Z with atomic number 10 and atomic mass 22
Explanation:
Isotopy is the existence of two or more atoms of the same element having the same atomic number but different mass numbers due to the differences in the number of neutrons in their various nuclei.
- Isotopes of an element have the same electronic configuration.
- They share the same chemical properties
- They only differ in their masses.
So, Element X and Z with atomic number 10 which is their number of electrons are isotopes. Their mass number, 21 and 22 differs.
The empirical formula for the compound is - P₂O₅
the empirical formula is the simplest ratio of whole numbers of components in a compound.
molecular formula is the actual ratio of components in a compound.
we have to first find the number of empirical units in the molecular formula
molecular mass - 283.89 g/mol
mass of empirical formula - 283.8 g
number of empirical units - 283.89 g/mol / 283.8 g
number of empirical units - 1.000
therefore empirical formula = molecular formula
molecular formula - P₂O₅
Endothermic reaction is the reaction in which the system absorbs energy. The system absorbs heat and cools the surroundings. Reactants are the substances that are involved in the reaction and at the end of the reaction product are formed.
In the endothermic reaction because heat is absorbed , the products have a higher heat.
Answer:
14.33 g
Explanation:
Solve this problem based on the stoichiometry of the reaction.
To do that we need the molecular weight of the masses involved and then calculate the number of moles, find the limiting reagent and finally calculate the mass of AgCl.
2 AgNO₃ + CaCl₂ ⇒ Ca(NO₃)₂ + 2 AgCl
mass, g 6.97 6.39 ?
MW ,g/mol 169.87 110.98 143.32
mol =m/MW 0.10 0.06 0.10
From the table above AgNO₃ is the limiting reagent and we will produce 0.10 mol AgCl which is a mass :
0.10 mol x 143.32 g/mol = 14.33 g
