Answer:
C) 1.15 × 10⁻⁷ mm
Explanation:
Step 1: Given data
Average distance between nitrogen and oxygen atoms: 115 pm
Step 2: Convert the distance to meters (SI base unit)
We will use the conversion factor 1 m = 10¹² pm.
115 pm × (1 m/10¹² pm) = 1.15 × 10⁻¹⁰ m
Step 3: Convert the distance to millimeters
We will use the conversion factor 1 m = 10³ mm.
1.15 × 10⁻¹⁰ m × (10³ mm/1 m) = 1.15 × 10⁻⁷ mm
1 mole of CO2 has 6.02 x 10^23 molecules of CO2. Say x moles of CO2 has 3.0x10^23 molecules of CO2. Therefore x = 3/6.02 = 0.50. M = 0.50 * (12 + 2x16) = 0.50 * 44 = 22g
When children are small they are given vaccines that are usually dead viruses given to the body. These viruses don't cause damage to body and the body takes it as a real virus and prepare antibodies in the body but when a certain real disease or virus is in the body , the already presented antibodies fight with them for the protection of the body. These antibodies remain in the body so that when a disease or virus attacks the body the antibodies are already geared up to fight against them. Thus antibodies protect the body against invading microbes or viruses.
Answer:
Explanation: Atoms are the building blocks of all matter. They consist of three sub-atomic particles: protons, neutrons and electrons. Protons and neutrons are found in the nucleus of an atom. Electrons are found in energy levels around the nucleus as shown in the diagram representing a carbon atom with 6 protons, 6 neutrons and 6 electrons.
Sub-atomic particles
Particle Whereabouts in atom Relative mass Charge
Proton Nucleus 1 +1
Neutron Nucleus 1 0
Electron Outside the nucleus 1/1840 -1
Diagram of carbon atom - nucleus with electrons orbiting
Diagram of carbon atom - nucleus with electrons orbiting
In chemistry we are particularly interested in electrons. As you will see later, this is because chemical reactions involve the rearrangement of electrons. Nuclei of atoms (protons and neutrons) usually remain unchanged (except in radioactive decay).
Electrons are arranged in atoms according to their energies. This is called the electronic structure or electronic configuration of the atom. A crude but still useful model says the electrons can be in different energy levels. Electrons in a particular energy level all have the same energy as one another. The lowest energy level can accommodate up to 2 electrons. The second level can accommodate up to 8 electrons. The third level can accommodate up to 18 electrons. The diagram shows the situation for a sulfur atom.
Electronic configuration of sulfur including energy level diagram
Answer : The correct option is, (D) double replacement reaction
Explanation :
Synthesis reaction : A chemical reaction where multiple substances or reactants combine to form a single product.
It is represented as,
Decomposition reaction : A chemical reaction in which larger reactant decomposes to give two or more than two products.
It is represented as,
Single replacement reaction : A chemical reaction in which the more reactive element replace the less reactive element.
It is represented as,
In this reaction, A is more reactive element and B is less reactive element.
Double replacement reaction : It is a type of chemical reaction where a positive cation and a negative anion of two reactants exchange places to form two new products.
It is represented as,
(X and A are the cations, Y and B are the anions)
The given reaction is:
This reaction is a double displacement reaction.
