Which of the following has the smallest atomic radius group of answer choices?
Helium
What is the trend for atomic radius down a group?
In general, atomic radius decreases across a period and increases down a group. Across a period, effective nuclear charge increases as electron shielding remains constant.
Why does atomic radius increase as you go down Group 2?
Going down group 2: there are more filled shells between the nucleus and the outer electrons … so the electrons in the higher energy levels are further from the nucleus … the atomic radius increases.
What is the trend in atomic radius down Group 2?
Group 2 Elements are called Alkali Earth Metals. They are called s-block elements because their highest energy electrons appear in the s subshell. Progressing down group 2, the atomic radius increases due to the extra shell of electrons for each element. Going down the group, the first ionisation energy decreases.
What happens when potassium touches water?
When potassium is added to water, the metal melts and floats. It moves around very quickly on the surface of the water. The hydrogen ignites instantly. The metal is also set on fire, with sparks and a lilac flame.
Does lithium react violently with water?
Lithium reacts intensely with water, forming lithium hydroxide and highly flammable hydrogen. The colourless solution is highly alkalic. The white powder that forms releases hydrogen gas upon later reaction with water, in amounts of 2800 liter per kilogram hydride.
Why does potassium catch fire and burn explosively in water?
Metal oxides that are soluble in water dissolve in it to further form metal hydroxide. Metals like potassium and sodium react violently with cold water. In case of sodium and potassium, the reaction is so violent and exothermic, that evolved hydrogen immediately catches fire.”
What is the most explosive metal?
Explosive antimony is an allotrope of the chemical element antimony that is so sensitive to shocks that it explodes when scratched or subjected to sudden heating. The allotrope was first described in 1855.
What metal reacts most vigorously with water?
Sodium