In comparison to boron, beryllium has greater nuclear charge or lesser

Explanation:

Beryllium contains 4 electrons throughout the s1 s2 nuclei, which are completely loaded and both atoms are combined, as opposed to boron. Therefore, when all electrodes are coupled and orbitals are loaded down, it would have less nuclear charge and also have greater ionization.

out of these options:

ability to burn paper

pure sodium reacting violently with water

the boiling point of water

helium does not tend to react with anything

i would say this is a physical property:

helium does not tend to react with anything

why? :

i said helium does not tend to react with anything because well, it reacts to ! but ability to burn paper, pure sodium reacting violently with water, & the boiling point of water are chemical or

physical properties: the properties of a substance that can be observed without changing the chemical makeup of the substance

chemical properties: properties of a substance relating to the chemical nature and reactivity of the substance

answer:

technetium is the most reactive. this is followed by silver. the least reactive out of these three elements is strontium.