Answer:
Atom is the building block of matter. The atom itself made up of subatomic particles electron, proton and neutron.
Explanation:
Long time ago, Greek philosopher thoughts that matter can be divided into smaller particles until a point is reached when the basic unit is obtained which can not be further sub divided. A Greek philosopher Democritus called these basic units "Atom".
Later on modern research showed that atom could be divided into smaller particles electron, proton and neutron. These smaller particles are called sub-atomic particles of atom.
Atoms are the fundamental unit of matter. Every thing in the universe that occupy space and have mass is called matter. we can say that every matter is composed of atoms. while the atom is composed of subatomic particles called electron proton and neutron.
Electron:
The electron is subatomic particle that revolve around outside the nucleus and has negligible mass. It has a negative charge.
Symbol = e-
Mass= 9.10938356×10-31 Kg
It was discovered by j. j. Thomson in 1897 during the study of cathode ray properties.
Proton and Neutron:
An atom consist of positively charged central core (nucleus) that is made up of Proton and neutron. Proton has positive charge while neutron is electrically neutral. Proton is discovered by Rutherford while neutron is discovered by James Chadwick in 1932.
Symbol of proton= P+
Symbol of neutron= n0
Mass of proton=1.672623×10-27 Kg
Mass of neutron=1.674929×10-27 Kg
All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example if neutral atom has 6 protons than it must have 6 electrons.
Strong Acid has a lower pH level than a weak acid, weak acid pH level will be closer to 7 than the strong acid. Weak acid does not dissociate completely, therefore a weaker proton donor, thus higher pKa. Strong acids dissociates completely and release all of their hydrogen atom when dissolve in water.
6.6 × 
J = 6.2 × 
British thermal units
First of all, we should know that 1 British thermal unit = 1055 Joules.
From question, heat = 6.6 × J
1 BTU = 1055 J
6.6 × J = 
× 6.6 × British thermal units
= 6.2 × British thermal units
1000 Joules = 1 kilojoule
A kilojoule is a unit of measure of energy, in the equal way that kilometers degree distance. meals energy used to be measured in energy and some international locations still use those gadgets.
The power we get from foods and drinks is measured in kilojoules. that is the metric time period for calorie. Kilojoules and energy constitute the equal aspect. One calorie is ready four kilojoules.
Calorie a unit for measuring warmth same to the quantity of warmth required to elevate the temperature of one gram of water one diploma Celsius.
Learn more about kilojoules here :- brainly.com/question/490326
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