321732
General characteristics of lanthanoids
I. These are silvery white soft metals.
II. They tarnish rapidly in air.
III. The hardness decreases with increasing atomic number, Samarium being steel hard.
IV. Their melting points range betwen 1000 to \(\mathrm{1200 \mathrm{~K}}\) but samarium melts at \(\mathrm{1623 \mathrm{~K}}\).
Identify the incorrect statement (choose the appropriate option)
321732
General characteristics of lanthanoids
I. These are silvery white soft metals.
II. They tarnish rapidly in air.
III. The hardness decreases with increasing atomic number, Samarium being steel hard.
IV. Their melting points range betwen 1000 to \(\mathrm{1200 \mathrm{~K}}\) but samarium melts at \(\mathrm{1623 \mathrm{~K}}\).
Identify the incorrect statement (choose the appropriate option)
321732
General characteristics of lanthanoids
I. These are silvery white soft metals.
II. They tarnish rapidly in air.
III. The hardness decreases with increasing atomic number, Samarium being steel hard.
IV. Their melting points range betwen 1000 to \(\mathrm{1200 \mathrm{~K}}\) but samarium melts at \(\mathrm{1623 \mathrm{~K}}\).
Identify the incorrect statement (choose the appropriate option)
321732
General characteristics of lanthanoids
I. These are silvery white soft metals.
II. They tarnish rapidly in air.
III. The hardness decreases with increasing atomic number, Samarium being steel hard.
IV. Their melting points range betwen 1000 to \(\mathrm{1200 \mathrm{~K}}\) but samarium melts at \(\mathrm{1623 \mathrm{~K}}\).
Identify the incorrect statement (choose the appropriate option)