Advertisements
Advertisements
Question
What is variable valency? Name two elements having variable valency and state their valencies.
Solution
Variable valency: Some elements exhibit more than one valency. They are said to have variable valency, e.g. Iron, copper, tin, lead.
Iron Fe Fe2+ or Fe3+
Copper cu cu+ or cu2+
APPEARS IN
RELATED QUESTIONS
Explain the Mass number with example.
The mass number of an element is 23 and it contains 11 electrons. What is the number of protons and neutrons in it? What is the atomic number of the element?
Elements X, Y and Z have atomic numbers 6, 9 and 12 respectively. Which one:
- Forms an anion
- Forms a cation
- Has four electrons in its valence shell?
Match the atomic numbers 4,8,10,15 and 19 with each of the following:
An element which does not form ion
Define the term of atomic number.
Elements X, Y, Z have atomic numbers 6, 9 and 12 respectively. Which one:
- forms anion – negative ion;
- forms cation – positive ion;
- has 4 electrons in the outermost orbit. [Y, Z, X]
What is atomic number?
What are nucleons? How many nucleons are present in Phosphorous? Draw its structure.
Which of the following are true for an element?
- Atomic number = number of protons + number of electrons
- Mass number = number of protons + number of neutrons
- Atomic mass = number of protons = number of neutrons
- Atomic number = number of protons = number of electrons
Name the 3 sub-atomic particles of an atom.
