Question : Which of the following statements is not correct regarding the alkali metals?
Option 1: All the alkali metals are silvery white, soft and light metals.
Option 2: The ionisation enthalpies of the alkali metals are considerably low and decrease down the group.
Option 3: Group 1 metals are known as alkali metals.
Option 4: All the alkali metals have two valence electrons.
Correct Answer: All the alkali metals have two valence electrons.
Solution : The incorrect statement is All the alkali metals have two valence electrons.
Group 1 of the periodic table comprises all alkali metals, which have a single valence electron. Electrons in the atom's outermost orbit are known as valence electrons. Group 1 of the periodic table contains the alkali metals hydrogen (H), lithium (Li), sodium (Na), potassium (K), caesium (Cs), rubidium (Rb), and francium (Fr).
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Question : Electrons in the highest energy level of an atom are called ________.
Option 1: Valence protons
Option 2: Orbital protons
Option 3: Valence electrons
Option 4: Orbital electrons
Question : An electron microscope gives higher magnifications than an optical microscope because:
Option 1: The velocity of electrons is smaller than that of light.
Option 2: The wavelength of electrons is smaller as compared to the wavelength of visible light.
Option 3: The electrons have more energy than the light particulars.
Option 4: The electron microscope uses more powerful lenses.
Question : Which of the following statements is correct?
Option 1: Atomic radius increases across a period and decreases down a group in the periodic table.
Option 2: Atomic radius decreases across a period and increases down a group in the periodic table.
Option 3: Atomic radius decreases across a period and down a group in the periodic table.
Option 4: Atomic radius increases across a period and increases down a group in the periodic table.
Question : Directions: In the following question below, some statements are followed by some conclusions. Taking the given statements to be true, even if they seem to be at variance from commonly known facts, read all the conclusions and then decide which of the given conclusions logically follows from the given statements. Statements: I. All whites are liquid. II. Some poles are white. Conclusions: I. All poles are liquid. II. Some liquids are poles. III. All liquids are white.
Option 1: Only conclusion I follows
Option 2: Only conclusion II follows
Option 3: Only conclusion II and III follow
Option 4: Neither conclusion follows
Question : Identify whether the given statements about ionisation energy are correct or incorrect.
Statement A: The ionisation energy of an atom is the amount of energy that is required to remove an electron from a mole of atoms in the gas phase.
Statement B: The ionisation energy increases from top to bottom in groups and decreases from left to right across a period.
Option 1: Both Statements A and B are correct.
Option 2: Only Statement A is correct.
Option 3: Both Statements A and B are incorrect.
Option 4: Only Statement B is correct.
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