22-yes, they belong to the same group
23- they are metals
24-Atoms of group 1 elements all have one electron in their outer shell. This means Na and K have the same valence electrons.
25-Metals are solids at room temperature, therefore Na and K are solid.
26- mass number=A=235
Protons=z=92
Neutrons=mass number-protons
Neutrons=A-Z
Neutrons=235-92
Neutrons=143
Answer:
a tendency to do nothing or to remain unchanged.
Explanation:
Answer: A cold compress used by athletes is an endothermic reaction.
Explanation:
A pack of cold compress used by athletes contains water that holds another bag or tube inside it which is filled with ammonium nitrate fertilizer.
So, on hitting the cold compress the tube breaks down due to which fertilizer gets mixed with water. This mixture absorbs the heat when placed on the area of body having pain, strain or bump.
As a result, we tend to feel cold at the affected area of our body.
Thus, we can conclude that a cold compress used by athletes is an endothermic reaction.
There had been new discoveries of chemicals that have been added to the periodic table in recent years
All matter (solid, liquid or gas) has a definite shape and occupies a specific volume.
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Hope it helps...</h2>