Share & grow the world's knowledge!
We want to connect the people who have knowledge to the people who need it, to bring together people with different perspectives so they can understand each other better, and to empower everyone to share their knowledge.
Determine the formula unit mass of the following substances. (i) Ammonium nitrate (NH4NO3), used as a nitrogen fertiliser, which is essential for plant growth. (ii) Phosphoric acid (H3PO4), used to make phosphate fertiliser and detergents. (iii) Sodium hydrogencarbonate (NaHCO3), used to relieve acidity and helps in digestion.
For ammonium nitrate NH4NO3, the mass equals two nitrogens, four hydrogens and three oxygens, totaling 28 plus 4 plus 48, which equals 80 u. For phosphoric acid H3PO4, the mass equals three hydrogens, one phosphorus and four oxygens, totaling 3 plus 31 plus 64, which equals 98 u. For sodium hydrogenRead more
For ammonium nitrate NH4NO3, the mass equals two nitrogens, four hydrogens and three oxygens, totaling 28 plus 4 plus 48, which equals 80 u. For phosphoric acid H3PO4, the mass equals three hydrogens, one phosphorus and four oxygens, totaling 3 plus 31 plus 64, which equals 98 u. For sodium hydrogencarbonate NaHCO3, adding sodium 23, hydrogen 1, carbon 12 and three oxygens 48 gives 84 u.
For more NCERT Solutions of Class 9 Science Exploration Chapter 9 Atomic Foundations of Matter Question Answer (2026-27)
https://www.tiwariacademy.com/ncert-solutions/class-9/science/exploration-chapter-9/
See lessWhich term of the AP : 21, 18, 15, … is – 81? Also, is 0 a term of this AP? Give reasons for your answer.
For this AP, the first term is a = 21 and the common difference is d = 18 - 21 = -3. The nth term formula is tn = a + (n - 1)d. For tn = -81: 21 + (n - 1) x (-3) = -81 (n - 1) x (-3) = -102 n - 1 = 34, so n = 35. Thus, -81 is the 35th term. For tn = 0: 21 + (n - 1) x (-3) = 0 (n - 1) x (-3) = -21 nRead more
For this AP, the first term is a = 21 and the common difference is d = 18 – 21 = -3.
The nth term formula is tn = a + (n – 1)d.
For tn = -81:
21 + (n – 1) x (-3) = -81
(n – 1) x (-3) = -102
n – 1 = 34, so n = 35. Thus, -81 is the 35th term.
For tn = 0:
21 + (n – 1) x (-3) = 0
(n – 1) x (-3) = -21
n – 1 = 7, so n = 8.
Since n is a natural number, 0 is the 8th term.
For more NCERT Solutions of Class 9 Ganita Manjari Chapter 8 Predicting What Comes Next: Exploring Sequences and Progressions Question Answer (2026-27)
https://www.tiwariacademy.com/ncert-solutions/class-9/maths/ganita-manjari-chapter-8/
See lessFind the nth term of the AP: 11, 8, 5, 2 … Write the recursive rule for this AP.
In the given sequence, the first term is a = 11 and the common difference is d = 8 - 11 = -3. The explicit rule for the nth term is: tn = a + (n - 1)d tn = 11 + (n - 1) x (-3) tn = 11 - 3n + 3 tn = 14 - 3n. To write the recursive rule, each term after the first is obtained by adding the common diffeRead more
In the given sequence, the first term is a = 11 and the common difference is d = 8 – 11 = -3.
The explicit rule for the nth term is:
tn = a + (n – 1)d
tn = 11 + (n – 1) x (-3)
tn = 11 – 3n + 3
tn = 14 – 3n.
To write the recursive rule, each term after the first is obtained by adding the common difference:
t1 = 11 and tn = tn-1 – 3 for n >= 2.
For more NCERT Solutions of Class 9 Ganita Manjari Chapter 8 Predicting What Comes Next: Exploring Sequences and Progressions Question Answer (2026-27)
https://www.tiwariacademy.com/ncert-solutions/class-9/maths/ganita-manjari-chapter-8/
See lessAn AP consists of 50 terms in which the 3rd term is 12 and the last term is 106. Find the 29th term.
Given an AP of 50 terms: 3rd term: a + 2d = 12 50th term: a + 49d = 106 Subtracting the first equation from the second: (a + 49d) - (a + 2d) = 106 - 12 47d = 94, which gives d = 2. Substitute d = 2 into the first equation: a + 2 x 2 = 12 a = 12 - 4 = 8. Now, finding the 29th term: t29 = a + 28d = 8Read more
Given an AP of 50 terms:
3rd term: a + 2d = 12
50th term: a + 49d = 106
Subtracting the first equation from the second:
(a + 49d) – (a + 2d) = 106 – 12
47d = 94, which gives d = 2.
Substitute d = 2 into the first equation:
a + 2 x 2 = 12
a = 12 – 4 = 8.
Now, finding the 29th term:
t29 = a + 28d = 8 + 28 x 2 = 8 + 56 = 64.
Hence, the 29th term is 64.
For more NCERT Solutions of Class 9 Ganita Manjari Chapter 8 Predicting What Comes Next: Exploring Sequences and Progressions Question Answer (2026-27)
https://www.tiwariacademy.com/ncert-solutions/class-9/maths/ganita-manjari-chapter-8/
See lessHow many 2-digit numbers are divisible by 3? What is the sum of all these 2-digit numbers?
The two-digit numbers divisible by 3 form the sequence: 12, 15, 18, ..., 99. Here, a = 12, d = 3 and last term tn = 99. Using tn = a + (n - 1)d: 99 = 12 + (n - 1) x 3 87 = (n - 1) x 3 n - 1 = 29, so n = 30. There are 30 two-digit numbers divisible by 3. Their sum is given by Sn = (n / 2) x (a + tn):Read more
The two-digit numbers divisible by 3 form the sequence: 12, 15, 18, …, 99.
Here, a = 12, d = 3 and last term tn = 99.
Using tn = a + (n – 1)d:
99 = 12 + (n – 1) x 3
87 = (n – 1) x 3
n – 1 = 29, so n = 30.
There are 30 two-digit numbers divisible by 3.
Their sum is given by Sn = (n / 2) x (a + tn):
S30 = (30 / 2) x (12 + 99) = 15 x 111 = 1665.
Thus, the sum is 1665.
For more NCERT Solutions of Class 9 Ganita Manjari Chapter 8 Predicting What Comes Next: Exploring Sequences and Progressions Question Answer (2026-27)
https://www.tiwariacademy.com/ncert-solutions/class-9/maths/ganita-manjari-chapter-8/
See less