It requires about 3.9 eV of energy to break apart or severely damage a DNA molecule. When we damage the DNA in our skin cells, our bodies respond by directing a lot of blood to repair and replace the damaged cells, and our skin takes on a bright red glow (the tell-tale signs of sunburn). We also increase our risk of skin cancer.

a. What wavelength of light, in nm, has just enough energy to damage our DNA?
b. Which wavelengths of light are most important for a good sunscreen to block?
i. Wavelengths very close to the one calculated in the previous question
ii. Wavelengths greater than or equal to the one calculated in the previous question.
iii. Wavelengths less than or equal to the one calculated in the previous question.
iv. All wavelengths are equally important to block.
c. Only about 1% of the total power of sunlight that we are exposed to is in the form of dangerous radiation. Why is it that this 1% can cause damage to our DNA, but exposure to the other 99% leaves our DNA unharmed? How does this relate to the observations from the photoelectric effect

Consider the motion of the balloon and its air contents in terms of momentum. in step 1 above, the total momentum of the balloon and its contents was zero. recall that momentum = mv. both the balloon and the air inside it had a velocity of zero and therefore the total momentum was zero. now think about what happened when the air escaped from the balloon. a certain mass of air accelerated in one direction. in order to keep the total momentum of the system zero, the balloon itself (which has mass) had to accelerate in the opposite direction. use this scenario to you explain why the soda can rotates when the water squirts out of the escape holes. what was your hypothesis concerning the water-filled can? according to your data, do you think your hypothesis was correct? (be sure to refer to your data when answering this question.) summarize any difficulties or problems you had in performing the experiment that might have affected the results. describe how you might change the procedure to avoid these problems. give at least one more example of newton's third law in everyday life.

Nhumans, abo blood types refer to glycoproteins in the membranes of red blood cells. there are three alleles for this autosomal gene: ia, ib, and i. the ia allele codes for the a glycoprotein, the ib allele codes for the b glycoprotein, and the i allele doesn't code for any membrane glycoprotein. ia and ib are codominant, and i is recessive to both ia and ib. people with type a blood have the genotypes iaia or iai, people with type b blood are ibib or ibi, people with type ab blood are iaib, and people with type o blood are ii. if a woman with type ab blood marries a man with type o blood, which of the following blood types could their children possibly have? in humans, abo blood types refer to glycoproteins in the membranes of red blood cells. there are three alleles for this autosomal gene: ia, ib, and i. the ia allele codes for the a glycoprotein, the ib allele codes for the b glycoprotein, and the i allele doesn't code for any membrane glycoprotein. ia and ib are codominant, and i is recessive to both ia and ib. people with type a blood have the genotypes iaia or iai, people with type b blood are ibib or ibi, people with type ab blood are iaib, and people with type o blood are ii. if a woman with type ab blood marries a man with type o blood, which of the following blood types could their children possibly have? a, b, ab, and o ab and o a, b, and o a and b

What noticeable trend from this graph might be used to make a conclusion?