atomic number and mass number of oxygen

We know that the digits of a number, one by one in order from left to right decrease in value rapidly. Let us illustrate it by examples. Mass of a gold ornament is 23.473 g. Round off to (i) two decimal places, (ii) one decimal place. 23.473 g = (2 x 10) + (3 x 1) + Th..

Question: Define an odd number. Answer: A number when divided by 2 gives remainder 1 is called an odd number..

Assume the validity of the result for n equal to some arbitrary but fixed natural number, say, ..

Question: List the elements of the following sets and specify whether they are finite or infinite: Answer: (i) Since there is no natural number lying between 2 and 3, the set is a null set i.e. f . This is a finite set. (i) Since there are infinite numb..

Factorise x 2 - 15x + 1..

Factorise x 2 - 7x + 1..

If x:y=3:4 find value of (4x+3y) : (2x+5y..

n C 0 , n C 1 , ..... n C n are called binomial coefficients. n C 0 , n C 2 n C 4 , ..... are called even binomial coefficients. n C 1 , n C 3 , n C 5 .... are called odd binomial coefficient..

Question: For given sequence, suggest possible next three terms and find the general term. 7,11,15,... Answer: First term=7, Common difference =11 -7 = 15 - 11 = 4 The three terms form an A.P. Next three terms are 15 + 4 = 19, 19 + 4 = 23, 23 + 4 = 27 General term is = a + (n-1) d = ..

If n N, then ..