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Basic Concepts of Chemistry for MH-CET/ NEET

Published On: 3/28/2023

Author: Admin

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What is Measurement unit for Atomic Wight?

Atomic weight is measured in atomic Mass Unit (amu) , also called as daltons.

What is Relative Atomic Mass?

Atomic weight is also called as relative atomic mass of chemical element’s atoms to some standard

What is Molecular Mass / Atomic Mass?

Since 1961 the standard unit of atomic mass has been one-twelfth the mass of an atom of isotope carbon-12

Molecular Mass = Average relative Mass of one Molecule / (1/12 X mass of C-12 Atom)

Atomic Mass = Average relative Mass of one Atom / (1/12 X mass of C-12 Atom)

The original standard of atomic weight, established in the 19th century, was hydrogen, with a value of 1.

From about 1900 until 1961, oxygen was used as the reference standard, with an assigned value of 16. The unit of atomic mass was thereby defined as 1/16 the mass of an oxygen atom.

What is isotope?

An isotope is one of two or more species of atoms of the same chemical element that have different atomic mass numbers (protons + neutrons)

Who is john Dalton?

John Dalton developed a crude method for measuring the masses of the elements in a compound.

His law of multiple proportions states that when two elements form more than one compound, masses of one element that combine with a fixed mass of the other are in a ratio of small whole numbers.

What is valency?

A measurement of the power of an atom to combine with others, by the number of hydrogen atoms it can combine with or take the place of.

What is equivalent weight?

The equivalent weight of an element is its gram atomic weight divided by its valence (combining power).

Equivalent Weight = Molecular weight/ Valency

What is Molality and its formula?

Molality (m) is defined as the number of moles of solute per kilogram of solvent.

Formula Molality (m) = moles of solute / kilograms of solvent

What is Molarity and its formula?

Molarity means solution concentration i.e. the amount of solute in moles divided by the volume of solution in liters

M = moles of solute/liters of solution

What is equivalent weight of acid?

The equivalent weight of an acid is the mass of acid required to generate one mole of hydrogen (hydronium) ion in aqueous solution.

Equivalent weight of acid= Molecular Mass / Basicity

What is equivalent weight of base?

The equivalent weight of base is the weight of compound that contains one equivalent of hydroxide ion (OH-)

Equivalent weight of acid= Molecular Mass / Acidity

Periodic Table for Elements with Atomic Mass, symbol, atomic number and classification.

element	symbol	atomic number	atomic weight	Classification
hydrogen	H	1	[1.00784, 1.00811]	Halogen
helium	He	2	4.002602	Nobel Gas
lithium	Li	3	[6.938, 6.997]	Alkali Metal
beryllium	Be	4	9.0121831	Alkaline Earth
boron	B	5	[10.806, 10.821]	Metalloid
carbon	C	6	[12.0096, 12.0116]	Non metal
nitrogen	N	7	[14.00643, 14.00728]	Non Metal
oxygen	O	8	[15.99903, 15.99977]	Non Metal
fluorine	F	9	18.998403163	Halogen
neon	Ne	10	20.1797	Nobel Gas
sodium	Na	11	22.98976928	Alkali Metal
magnesium	Mg	12	[24.304, 24.307]	Alkaline Earth
aluminum (aluminium)	Al	13	26.9815385	Basic Metal
silicon	Si	14	[28.084, 28.086]	Metalloid
phosphorus	P	15	30.973761998	Non metal
sulfur (sulphur)	S	16	[32.059, 32.076]	Non metal
chlorine	Cl	17	[35.446, 35.457]	Halogen
argon	Ar	18	39.948	Nobel Gas
potassium	K	19	39.0983	Alkali Metal
calcium	Ca	20	40.078	Alkaline Earth
scandium	Sc	21	44.955908	Transition Metal
titanium	Ti	22	47.867	Transition Metal
vanadium	V	23	50.9415	Transition Metal
chromium	Cr	24	51.9961	Transition Metal
manganese	Mn	25	54.938044	Transition Metal
iron	Fe	26	55.845	Transition Metal
cobalt	Co	27	58.933194	Transition Metal
nickel	Ni	28	58.6934	Transition Metal
copper	Cu	29	63.546	Transition Metal
zinc	Zn	30	65.38	Transition Metal
gallium	Ga	31	69.723	Basic Metal
germanium	Ge	32	72.63	Metalloid
arsenic	As	33	74.921595	Metalloid
selenium	Se	34	78.971	Non metal
bromine	Br	35	[79.901, 79.907]	Halogen
krypton	Kr	36	83.798	Nobel Gas
rubidium	Rb	37	85.4678	Alkali Metal
strontium	Sr	38	87.62	Alkaline Earth
yttrium	Y	39	88.90594	Transition Metal
zirconium	Zr	40	91.224	Transition Metal
niobium	Nb	41	92.90637	Transition Metal
molybdenum	Mo	42	95.95	Transition Metal
technetium	Tc	43	97	Transition Metal
ruthenium	Ru	44	101.07	Transition Metal
rhodium	Rh	45	102.9055	Transition Metal
palladium	Pd	46	106.42	Transition Metal
silver	Ag	47	107.8682	Transition Metal
cadmium	Cd	48	112.414	Transition Metal
indium	In	49	114.818	Basic Metal
tin	Sn	50	118.71	Basic Metal
antimony	Sb	51	121.76	Metalloid
tellurium	Te	52	127.6	Metalloid
iodine	I	53	126.90447	Halogen
xenon	Xe	54	131.293	Nobel Gas
cesium (caesium)	Cs	55	132.90545196	Alkali Metal
barium	Ba	56	137.327	Alkaline Earth
lanthanum	La	57	138.90547	Lanthanide
cerium	Ce	58	140.116	Lanthanide
praseodymium	Pr	59	140.90766	Lanthanide
neodymium	Nd	60	144.242	Lanthanide
promethium	Pm	61	145	Lanthanide
samarium	Sm	62	150.36	Lanthanide
europium	Eu	63	151.964	Lanthanide
gadolinium	Gd	64	157.25	Lanthanide
terbium	Tb	65	158.92535	Lanthanide
dysprosium	Dy	66	162.5	Lanthanide
holmium	Ho	67	164.93033	Lanthanide
erbium	Er	68	167.259	Lanthanide
thulium	Tm	69	168.93422	Lanthanide
ytterbium	Yb	70	173.045	Lanthanide
lutetium	Lu	71	174.9668	Lanthanide
hafnium	Hf	72	178.49	Transition Metal
tantalum	Ta	73	180.94788	Transition Metal
tungsten (wolfram)	W	74	183.84	Transition Metal
rhenium	Re	75	186.207	Transition Metal
osmium	Os	76	190.23	Transition Metal
iridium	Ir	77	192.217	Transition Metal
platinum	Pt	78	195.084	Transition Metal
gold	Au	79	196.966569	Transition Metal
mercury	Hg	80	200.592	Transition Metal
thallium	Tl	81	[204.382, 204.385]	Basic Metal
lead	Pb	82	207.2	Basic Metal
bismuth	Bi	83	208.9804	Basic Metal
polonium	Po	84	209	Metalloid
astatine	At	85	210	Halogen
radon	Rn	86	222	Nobel Gas
francium	Fr	87	223	Alkali Metal
radium	Ra	88	226	Alkaline Earth
actinium	Ac	89	227	Actinide
thorium	Th	90	232.0377	Actinide
protactinium	Pa	91	231.03588	Actinide
uranium	U	92	238.02891	Actinide
neptunium	Np	93	237	Actinide
plutonium	Pu	94	244	Actinide
americium	Am	95	243	Actinide
curium	Cm	96	247	Actinide
berkelium	Bk	97	247	Actinide
californium	Cf	98	251	Actinide
einsteinium	Es	99	252	Actinide
fermium	Fm	100	257	Actinide
mendelevium	Md	101	258	Actinide
nobelium	No	102	259	Actinide
lawrencium	Lr	103	262	Actinide
rutherfordium	Rf	104	263	Transition Metal
dubnium	Db	105	268	Transition Metal
seaborgium	Sg	106	271	Transition Metal
bohrium	Bh	107	270	Transition Metal
hassium	Hs	108	270	Transition Metal
meitnerium	Mt	109	278	Transition Metal
darmstadtium	Ds	110	281	Transition Metal
roentgenium	Rg	111	281	Transition Metal
copernicium	Cn	112	285	Transition Metal
ununtrium	Uut	113	286	Basic Metal
flerovium	Fl	114	289	Basic Metal
ununpentium	Uup	115	289	Basic Metal
livermorium	Lv	116	293	Basic Metal
ununseptium	Uus	117	294	Halogen
ununoctium	Uuo	118	294	Nobel Gas