chemical substances class 7

symbol of sodium

• k

• Fe

• Na

• Ag

balance the equation - H2 + O2 = H2O

• 2H2 + O2 = 2H2O

• 3H2 + O2 = 3H2O

• H2 + O = H2o

decomposition reaction is just revers of combination reaction

• true

• false

name the ion =

ch3coo-

(a)  

what is neutralisation reaction

• a reaction in which two or more substances combine to form a new substances

• a reaction between acid and base

• a reaction in which a strong element displaces a weak element

what is the charge of zinc (Zn)

• 2+

• 3-

• 4-

• 8+

what is the name of -

CaCo3

• calcium chloride

• calcium phosphate

• calcium carbonate

what we have to pass from water ( 2H2O ) to separate hydrogen ( H+) and oxygen (O2- )

(a)  

what is the symbol of sodium chloride

• NaCl

• 2NaCl

• Na2Cl2

• NaCl2

NaOH + HCL =

• NaCl + H2O

• NaCl + H2O2

• Na2Cl + 2H2O