Paragraphs 10-14:
10:Consider helium again. Most helium atoms have two neutrons in addition to two protons. Therefore the mass of most helium atoms is 4 atomic mass units (2 amu for the protons + 2 amu for the neutrons). However, some helium atoms have more or less than two neutrons. Atoms with the same number of protons but different numbers of neutrons are called isotopes. Because the number of neutrons can vary for a given element, the mass numbers of different atoms of an element may also vary. For example, some helium atoms have three neutrons instead of two. Therefore, they have a different mass number than the one given in the figure above..
11:Q: What is the mass number of a helium atom that has three neutrons?
12:A: The mass number is the number of protons plus the number of neutrons. For helium atoms with three neutrons, the mass number is 2 (protons) + 3 (neutrons) = 5.
13:Q: How would you represent this isotope of helium to show its atomic number and mass number?
14:A: You would represent it by the element’s symbol and both numbers, with the mass number on top and the atomic number on the bottom:
5 He
2
Question:
There are two atoms of nitrogen: atom A and atom B. Nitrogen has an atomic number of 7. Atom A has a mass number of 15 and atom B has a mass number of 16. Are the two atoms isotopes? Why or why not?
EXTRA HELP
What is an isotope? What is different about atoms A and B? Use information from paragraphs 10-14 for additional help.
Answers: 3
Biology, 21.06.2019 15:00, asra44
Dna is the genetic material that makes up living things, and folic acid plays an important role in the information of dna. jon wants to study the effect of folic acid on dna formation in microbes. which statement accurately describes the variables in this study
Answers: 2
Biology, 22.06.2019 08:00, rosepotato789
Two students are working together on an experiment that measures the effect of different liquid fertilizers on the thickness of plants’ stems. which is most likely to result in the greatest amount of error in their scientific experiment? a. one student measures the plant stem widths by using calipers. the other student measures the widths of the same plant stems again by using a different pair of calipers. b. one student measures the plant stem widths by using calipers. the other student types the measurements as they are taken into a computer spreadsheet. c. one student weighs liquids for the experiment by using a calibrated scale. the other student weighs liquids for the experiment by using a different calibrated scale.
Answers: 1
Paragraphs 10-14:
10:Consider helium again. Most helium atoms have two neutrons in addition to two...
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