Which of the following group contains alkali metals?
a) IIA
b) IIIA
c) VIIA
d) IA
The reaction between sodium and water produces…….
a) H2
b) Na2CO3
c)NaCl
d) O2
Photosynthesis in plants is…….
a) synthesis
b) decomposition
c) endothermic
The reaction between magnesium and hydrochloric acid is:
Mg +2HCl -------àMgCl2 + H2
Which substance indicates the reaction has taken place?
a) Mg
b)HCl
c) H2
d) MgCl2
Which of the following reaction is unbalanced?
a) C + O2 ----à CO2
b) H2 + Cl2----à 2HCl
c) KClO3 ----àKCl + O2
d)Ca + S---àCaS
An endothermic reaction occurs when……
a) carbon burns in air
b) electrical discharges in the atmosphere nitrogen combines with oxygen
c) natural gas burns in air
d) hydrogen combines with oxygen to form water
How
by at 2025-02-08 19:04:37