A. Lyases
B. Ligases
C. Lipases
D. Hydrolases
A. acetaldehyde
B. ethyl alcohol
C. methyl alcohol
D. acetone
A. they cast shadow
B. they possess momentum
C. they are negatively charged
D. all of the above
A. 3 – 7 days
B. 2 -3 days
C. 3 – 7 years
D. 2 – 3 years
A. HF
B. HBr
C. HC
D. HI
The chemical compound silicon dioxide, also known as silica (from the Latin silex), is an oxide of silicon with a chemical formula of SiO2 and has been known for its hardness since antiquity. Silica is most commonly found in nature as sand or quartz, as well as in the cell walls of diatoms.
A. CaO+ SiO2——> CaSiO3
B. 2FeS+3O2——–> 2Fe+ SO2
C. FeSiO3———> FeSiO3
D. Fe2O3+ 3CO——–> 2Fe+ 3CO2