What is the change of state A
Crystallising
sublimating
condensing
Freezing
Name a greenhouse gas in the atmosphere（小写英文，写英文名称）
what is the name of CH3CH2CH2CH3?
Name the noble gas that makes up about 1% of the atmosphere
Nitrogen
radon
argon
helium
What is the product of reacting methane with bromine other than bromomethane
HBr
H2
H2O
O2
State the appearance of the iron wool after one week
white
Black
Red-brown
Yellow
What is the reaction type of methane reacting with bromine?
addition
decomposition
substitution
condensation
What is the condition of reacting bromine with methane?
Radio wave
H3PO4
UV light
AlLiH4 in dry ether
Explain why incomplete combustion of C2H6cause a problem for humans?
Because C2H6 is corrosive
Because CO is produced which can reduce the ability of haemoglobin to carry oxygen
Because human are addictive to C2H6
Which Group 7 element is a liquid at room temperature?
chlorine
Bromine
Iodine
Fluorine
What is the color of solid iodine?
Purple
dark brown
dark grey
Black
Zn react with HNO3
Excess zinc is used as for fun
excess zinc is used to react with Zn(NO3)2
Excess zinc is used to ensure all nitric acid reacts
Excess zinc is used to make sure that H2 produces
Silicon dioxide has a high melting point because it has a ______ structure with strong covalent bonds.
What are two observations when magnesium burns in oxygen?
Bright white flame and white powder formed
Blue flame and black residue
Green flame and gas released
No visible change
So that the solid dissolves more quickly
So that the temperature will decrease very soon
So that the water can with ammonium nitrate
So that more ammonium nitrate will dissolve
What type of reaction is PbCO₃ → PbO + CO₂?
Combustion
neutralisation
displacement
thermal decomposition