Answer 1
The sample will dissolve in more than 1 minute.
Explanation :-
Generally Solubility and rate of solubility of substances increase with the increase in temperature. So lower the temperature less fast will it dissolve in the same amount of water.
Since at 50 C it takes 1 minute to dissolve, at 20 C which is lower temperature it will take more time to dissolve.
Answer 2
Transition metals
Explanation:-
Hardness depends on the extent of metallic bonding for metals. More the number of electrons more the metallic bonding.
Alkali metals with just 1 valence electron have weak metallic bonding. Alkaline earth metals have just 2 valence electrons. Transition elements has more electrons in penultimate shell and valence shell than lanthanides. Transition metals with most metallic bonding are the hardest
Answer:
5f14 6d10 7s2 7p6
Explanation:
This is because oganesson is a noble gas and element of group 18 which does not occur or is not produced naturally. It is produced in an experiment. It is a gas at room temperature and it has atomic number of 118. It is harmful and a radioactive gas due to it's radioactive properties and it is produced in small amound
It’s B
Silicon is used for electronic devices because it is an element with very special properties. One of it's most important properties is that it is a semiconductor.
A hydrogen fuel cell is more efficient than a combustion reaction because very little of the released energy is released as "Heat". <span>When used at home, a fuel cell eliminates the need for "An Electrical grid"
Hope this helps!</span>
