Answer:
Halogens
Explanation:
From the given choices, the halogens will have the smallest radius within the same period.
The size of an atom is estimated by the atomic radius. This is taken as half of the inter-nuclear distance between two covalently bonded atoms of non-metallic elements or half of the distance between two nuclei in the solid state.
- Across a period in the periodic table, atomic radii decrease progressively from left to right.
- Down a group from top to bottom, atomic radii increase progressively due to the addition of successive shells.
Since halogen is the right most group from the choices given, it will have the smallest radius.
Reactivity. It is the ability of matter to combine chemically with other substances.
Answer:
he predicted the properties from known elements above and belws the unknown in the same group
Explanation:
What allowed Mendeleev to make predictions of undiscovered elements
He realized that an element on this table with one known element above it and one known element below it had to have properties between the two known elements
How did Mendeleev predict gallium and germanium?
Based on gaps in the periodic table Mendeleev deduced that in these gaps belonged elements yet to be discovered. Based on other elements below and above in the same group he predicted the existence of eka-aluminum, eka-boron, and eka-silicon, later to be named gallium (Ga), scandium (Sc), and germanium (Ge).
Particles of the substance have the most kinetic energy when the substance is(a)1. A gas. The part of the graph that represents where the substance has the least amount of potential energy is labeled(b)1. Solid.
Gas molecules have the highest average velocities among the three states of matter so gas has the highest kinetic energy. During freezing, a substance loses a lot of potential energy so solid has the least potential energy.
