Answer:
Increasing the surface area of the reactants
Explanation:
An increase in surface area of the reactant will always cause an increase in the rate of reaction. This is so because, an increase in the surface area of the reactant will cause the reactant particles to collide effectively thereby bringing about an increase in the reaction rate.
Collision theory suggests that for a reaction to occur, the reactant particles must collide with the right orientation. As the surface area of the reactants are increased, the reactants particles collide more with the right orientation bringing about definite increase in the rate of reaction.
No. When water first begins to cool down, it contracts. However, as it gets colder and eventually freezes, it begins to expand.
You can test this by freezing water in a water bottle: when you take it out of the freezer, the cap might have popped off or cracks may have formed in the sides of the bottle.
Answer: Water expands when frozen, not contracts.
Hi. You did not provide any response options. However, a PCR reaction proceeds as follows.
After the primers are added to the test tube containing the PCR components. This tube is placed in a device called a thermocycler. At that moment, the stage called denaturation will begin, where the thermocycler increases the temperature to the point of breaking the hydrogen bonds that hold the two strands of DNA together. The thermal cycler increases the temperature up to 96°C.
After that, the second step of the reaction begins. At that moment, the thermal cycler lowers the temperature to 55º - 65ºC, which is the ideal temperature for the primers to be able to attach themselves to the DNA strands, preparing them for the presence of the polymerase.
After that, the thermocycler raises the temperature to 72ºC, which is the ideal temperature for the DNA polymerase to work. At this stage, the DNA polymerase will use the DNA strand and the primer to build a new DNA strand, which will be annealed to the DNA strand used as a template.
These three steps will be repeated about 35 times, generating many copies of DNA.
