A student in a lab holds an iron nail over an open flame, and no reaction occurs. The nail is then filed, creating small pieces of iron shavings. These pieces burn brightly when placed over an open flame. Which statement accurately identifies one of the changes that occurs as a physical or chemical change?

A. Filing the nail is a chemical change because the composition of the material does not change but the general appearance of the iron does change.

B. Burning the iron filings is a chemical change because the composition of the material does not change but the general appearance of the iron does change.

C. Filing the nail is a physical change because the composition of the material does not change but the general appearance of the iron does change.

D. Burning the iron filings is a physical change because the composition of the material does not change but the general appearance of the iron does change.

Which of the following statements concerning the influence of culture on ethnic identity formation is accurate? a. one will reject ethnic identity if cultural stereotypes are encountered. b. if one’s ethnic city is different from the dominant cultural group, then one’s ethnic identity you will become weekend. c. if an the ethnic group is excepted by dominant culture, then ethnic identity formation can be a difficult process. d. similarity to the dominant culture can determine how easy it is for one to except ethnic differences.

Nanotechnology, the field of trying to build ultrasmall structures one atom at a time, has progressed in recent years. one potential application of nanotechnology is the construction of artificial cells. the simplest cells would probably mimic red blood cells, the body's oxygen transporters. for example, nanocontainers, perhaps constructed of carbon, could be pumped full of oxygen and injected into a person's bloodstream. if the person needed additional oxygen-due to a heart attack perhaps, or for the purpose of space travel-these containers could slowly release oxygen into the blood, allowing tissues that would otherwise die to remain alive. suppose that the nanocontainers were cubic and had an edge length of 24 nanometers. part a part complete what is the volume of one nanocontainer? (ignore the thickness of the nanocontainer's wall.) express your answer using two significant figures. v v = 1.4ă—10â’20 l previous answers correct significant figures feedback: your answer 1.3824â‹…10â’20 = 1.382ă—10â’20 l was either rounded differently or used a different number of significant figures than required for this part. if you need this result for any later calculation in this item, keep all the digits and round as the final step before submitting your answer. part b suppose that each nanocontainer could contain pure oxygen pressurized to a density of 81 g/l . how many grams of oxygen could be contained by each nanocontainer?

According to periodic trend, which of the following most likely has the highest ionization energy? kr be ni sc