Answer:
Stopwatches versus clocks. To improve reliability repeat the experiment multiple times according to an identical procedure. Record these steps so the experiment can be repeated at any time
Explanation:
Answer:sodium
Explanation: because its not hard to look on the PERIODIC TABLE
Answer:
Explanation:
exothermic reactions are the reactions which involve the release of energy.
the energy released can be of any forms ,for example heat,light .
all the combustion reactions are exothermic reactions
NH3 is soluble in water because it has the same amount of intermolecular forces as water. NH3 is a polar molecule and water is a polar molecule so they dissolve each other. NCl3 does not dissolve in water because it is a nonpolar molecule which is different with water. NCl3 is nonpolar due to the difference in electronegativities between 3 atoms of Cl and 1 atom if N2.
Physical change , the states are changing from liquid to gas
