In nuclear physics and nuclear chemistry, nuclearfission<span> is either a nuclear </span>reaction<span> or a radioactive decay process in which the nucleus of an atom splits into smaller parts (lighter nuclei).</span>
B- Carbon nitrogen and oxygen. All organisms are made up of carbon, oxygen is essential to breath, and nitrogen makes up most of earth's atmosphere.
Chemical reactions can be broadly classified into two categories from the context of heat requirement. These include; endothermic and exothermic reactions.
Endothermic reactions proceed with the absorption of heat while exothermic reactions are accompanied by the evolution of heat.
1) Oxidation of iron involves reaction of elemental iron with oxygen to form iron oxide (rust). This is essentially a corrosion reaction in which the metallic bonds in Fe are broken and new bonds between Fe and O are formed, This is an exothermic reaction
4Fe + 3O2 → 2Fe2O3
Ans D)
2) The process of condensation i.e. phase change liquid to solid (or gas to liquid) involves release of heat to the surroundings, hence it will be an exothermic reaction.
Ans B)
3) Specific heat is the amount of heat required to raise the temperature of 1 g of a substance by a 1 C. Typically, liquids and gases are used as coolants. For a coolant to be efficient, it must have a high specific heat.
Ans B)
Answer:
Attractive force is predominant between the two atoms
- The two hydrogen atoms approach each other to form a bond
- The two hydrogen atoms start to combine to form a hydrogen molecule
Repulsive force is predominant between the two atoms
- The potential energy of the system is positive
- The internuclear distance between the two hydrogen atoms is less than the bond length
Attractive and repulsive forces balance each other
- The two hydrogen atoms form a stable hydrogen molecule
- The potential energy of the system is at minimum
There is no interaction between the two atoms
- The hydrogen atoms are very far apart
Explanations:
- <em>increase in potential energy causes repulsion</em> between the atoms, whereas<em> decrease in potential energy causes attraction</em> between the atoms
- in order for the bonding to occur, the attractive forces must be greater than the repulsion forces.
- The potential energy is positive when the repulsion forces is greater. This is because the distance between the two atoms is smaller than the bond length
- The potential energy of the system is at its minimum because the attractive and repulsive forces balance out each other.
Hydrogen Bond is the bond based on intermolecular forces between H and F O and N
