- Trending Categories
Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Physics
Chemistry
Biology
Mathematics
English
Economics
Psychology
Social Studies
Fashion Studies
Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
Pick out the chemically most reactive elements from the given triads.
- Li, Na, K
- F, CI, Br
- Li and F
- Li and Br
- K and F
- K and Br
Correct Answer: (c) K and F
Explanation: As potassium (k) and fluorine (F) reacts with most of the other elements. Hence, they are most reactive in the given triads.
- Related Articles
- The elements whose oxides can turn phenolphthalein solution pink are:(a) Na and K (b) K and C (c) Na and S (d) K and P
- F, Cl and Br are elements each having seven valence electrons. Which of these:i. has the largest atomic radiusii. is most reactive?Justify your answer stating reason for each.
- Consider the following elements:Ca, Cl, Na, I, Li, Ba, Sr, K, Br Separate these elements into three groups (families) of similar properties. State one property in each case on the basis of which you have made your choice.
- Arrange the following elements in increasing order of their atomic radii.(a) Li, Be, F, N(b) Cl, At, Br I
- Solve the following equations and verify your answer:
(i) $\frac{5x-7}{3x}=2$
(ii) $\frac{3x+5}{2x+7}=4$ - Solve the following equations and verify your answer:
(i) $\frac{1-9y}{19-3y}=\frac{5}{8}$
(ii) $\frac{2x}{3x+1}=1$ - Write the degree of each of the following polynomials:
(i) $2x^3+5x^2-7$
(ii) $5x^2-3x+2$
(iii) $2x+x^2-8$
(iv) $\frac{1}{2}y^7-12y^6+48y^5-10$
(v) $3x^3+1$
(vi) $5$
(vii) $20x^3+12x^2y^2-10y^2+20$ - The concept of grouping elements into triads was given by _____________.
- Solve the following equations and verify your answer:
(i) $\frac{2y+5}{y+4}=1$
(ii) $\frac{2x+1}{3x-2}=\frac{5}{9}$ - Did Dobereiner’s triads also exist in the columns of Newlands’ Octaves? Compare and find out.
- Give the formulae of the compounds that would be formed by the combination of the following pairs of elements:(a) Mg and N2(b) Li and O2(c) Al and Cl2(d) K and H
- Na+ has completely filled K and L shells. Explain.
- Solve the following equations and verify your answer:
(i) $\frac{2x-3}{3x+2}=\frac{-2}{3}$
(ii) $\frac{2-y}{y+7}=\frac{3}{5}$ - Give the formulae of the stable binary compounds that would be formed by the combination of the following pairs of elements.(a) Mg and N2(b) Li and O2(c) Al and Cl2(d) K and O2
- Missing even and odd elements from the given arrays in C++
Advertisements