The question asks to identify the statement(s) that are NOT true for ionic compounds. We need to evaluate each given statement based on the known properties of ionic compounds.
Ionic compounds are formed by strong electrostatic forces of attraction between positively charged ions (cations) and negatively charged ions (anions). A large amount of energy is required to overcome these strong forces and break the crystal lattice. Therefore, ionic compounds generally have high melting and boiling points, not low. So, statement i is NOT true.
Due to the strong electrostatic forces, ionic compounds form a rigid crystal lattice. When external pressure or stress is applied, ions of like charge may come into alignment, leading to strong repulsive forces that cause the crystal to cleave or break. This property is known as brittleness. So, statement ii IS true.
As explained in statement i, the strong electrostatic forces between oppositely charged ions hold them together in a fixed, rigid structure, making them solids at room temperature and generally hard. So, statement iii IS true.
In the solid state, ions in an ionic compound are held in fixed positions and cannot move, so they do not conduct electricity. However, when an ionic compound is melted (molten state) or dissolved in a suitable solvent, the ions become free to move and can carry electric charge, thus conducting electricity. So, statement iv IS true.
Based on the evaluation, only statement i is NOT true for ionic compounds.
D) Only i
Simplify \(\sqrt{625}\) − \(\sqrt{324}\) + 33².
To simplify the given expression, we need to evaluate each term separately. This involves finding the square roots of 625 and 324, and calculating the square of 33. Once these values are found, we perform the addition and subtraction operations in the correct order.
We need to find the number that, when multiplied by itself, gives 625. We know that \(20^2 = 400\) and \(30^2 = 900\). The number ends in 5, so its square root must end in 5. Thus, \(25^2 = 625\).
\[ \sqrt{625} = 25 \]We need to find the number that, when multiplied by itself, gives 324. We know that \(10^2 = 100\) and \(20^2 = 400\). The number ends in 4, so its square root must end in 2 or 8. Let's try 18:
\[ 18 \times 18 = 324 \]\[ \sqrt{324} = 18 \]We need to calculate 33 multiplied by 33.
\[ 33 \times 33 = 1089 \]The original expression is \(\sqrt{625} - \sqrt{324} + 33^2\).
\[ 25 - 18 + 1089 \]First, perform the subtraction:
\[ 25 - 18 = 7 \]Then, perform the addition:\[ 7 + 1089 = 1096 \]C) 1096 is the correct answer, as derived from the step-by-step simplification of the expression.
The question asks to identify a specific cultural festival in India based on its characteristics: a ten-day duration, focus on classical dance, folk art, and light music, annual occurrence between February and March, and its venue at Shilpgram.
Correct Option: A) Taj Mahotsav
The question asks to identify the chemical process that occurs when a substance loses hydrogen during a reaction. This requires knowledge of the definitions of oxidation and reduction in terms of hydrogen transfer.
D) oxidised — When a substance loses hydrogen in a chemical reaction, it is said to be oxidised. For example, in the reaction of ethanol to ethanal: \( \text{CH}_3\text{CH}_2\text{OH} \rightarrow \text{CH}_3\text{CHO} + \text{H}_2 \), ethanol loses hydrogen and is thus oxidised.
Study the given diagram carefully and answer the following question. The numbers in different sections indicate the number of persons with different professions.
How many people are Gardeners but NOT Engineers?
To find the number of people who are Gardeners but NOT Engineers, we need to analyze the Venn diagram and identify the section that represents only Gardeners.
Correct Option: A) 68
A light ray is travelling from air medium to water medium (refractive index = 1.3) such that angle of incidence is x degree and angle of refraction is y degree. The value of ratio \( \frac{\sin y}{\sin x} \) is:
This problem involves the concept of refraction of light and Snell's Law. Snell's Law describes the relationship between the angles of incidence and refraction when light passes between two different media, and it uses the refractive indices of those media.
B) \( \frac{1}{1.3} \) is the correct answer, as derived from Snell's Law.
The value of \(\sqrt{1234321}\) =
The problem asks for the square root of a given number. The number \(1234321\) has a specific pattern that can be recognized to simplify the calculation of its square root. This pattern is related to numbers consisting only of ones.
Correct Option: A) 1111
To find the measure of each exterior angle of a regular polygon, we use the property that the sum of all exterior angles of any convex polygon is 360 degrees. For a regular polygon, all exterior angles are equal.
Correct Option: C) 60° is the measure of each exterior angle of a regular hexagon.
Janhvi and Pranitha are standing at the extreme ends of a row in which all the students are facing north. Only 26 students are standing between Janhvi and Ravi. Only 14 students are standing between Ravi and Pranitha. In total, how many students are standing in the line?
The problem describes a linear arrangement of students. We are given the number of students between Janhvi and Ravi, and between Ravi and Pranitha. Janhvi and Pranitha are at the extreme ends of the row. We need to find the total number of students. This is a simple linear arrangement problem where we add the number of students in each segment along with the individuals themselves.
Identify the key individuals and the number of students between them:
Since Janhvi and Pranitha are at the extreme ends, Ravi must be somewhere in between them. The total number of students can be calculated by summing the students in each segment and the three individuals (Janhvi, Ravi, Pranitha).
Calculate the total number of students:
\[ \text{Total students} = \text{Janhvi} + (\text{students between J and R}) + \text{Ravi} + (\text{students between R and P}) + \text{Pranitha} \]Substitute the given values:
\[ \text{Total students} = 1 + 26 + 1 + 14 + 1 \]Perform the addition:
\[ \text{Total students} = 1 + 26 + 1 + 14 + 1 = 43 \]A) 43 is the correct answer. This is obtained by adding the number of students between Janhvi and Ravi (26), the number of students between Ravi and Pranitha (14), and the three individuals themselves (Janhvi, Ravi, Pranitha), i.e., \(26 + 14 + 3 = 43\).
The question asks to identify the Indian athlete who received the "Woman of the Year Award" from World Athletics in December 2021 for her contributions to grooming talent and promoting sports among young girls and gender equality. This is a factual question related to sports awards and current affairs.
Correct Option: C) Anju Bobby George was awarded the "Woman of the Year Award" by World Athletics in December 2021. This recognition was for her efforts in grooming talent, encouraging young girls in India to take up sports, and fighting for gender equality.