Biology Ch 2.1 Mastering Biology

An uncharged atom of boron has an atomic number of 5 and an atomic mass of 11. How many protons does boron have?

5

What is the atomic number of an atom that has 6 protons, 6 neutrons, and 6 electrons?

6

The mass number of an atom is 15, and its atomic number is 7. The atom probably has...

8 neutrons in the nucleus.

Radioactive decay is likely to occur when ...

an atom has too many neutrons.

Which statement is true of the atom shown in the diagram? 1)An electron will move from the outer to the inner shell. 2)The atom has more than one valence electron. 3)The atom is in the excited state. 4)All of the above. 5)None of the above.

All of the above.

An atom has 6 electrons, 6 protons, and 6 neutrons. You can tell that this atom belongs to the element _____ because _____________________.

C; it has 6 protons.

A researcher is planning a study to determine if they can detect which regions of the brain are exhibiting abnormal activity in patients suffering from epilepsy. Use your knowledge of the scientific method and PET scans to match the following terms to their roles in the study.

1)Question Do individuals with epilepsy show altered rates of metabolic activity in different regions of their brains? 2)Hypothesis Patients with epilepsy have regional differences in their levels of brain metabolic activity. 3)Prediction If patients with epilepsy have regional differences in brain metabolic activity, then PET scans will show different patterns of brain activity between patients with epilepsy and patients without epilepsy. 4)Experimental group PET scans of individuals with epilepsy 5)Control group PET scans of individuals without epilepsy 6)Controlled variable Age of individuals

Fluorine's atomic number is 9 and its atomic mass is 19. How many neutrons does fluorine have?

10

An atom has 8 protons, 8 neutrons, and 8 electrons. Another isotope of the same element might have ...

10 neutrons.

The innermost electron shell of an atom can hold up to _____ electrons.

2

Copper has 29 protons, 34 neutrons, and 29 electrons. What is the atomic number of copper?

29

Which statement is true of atoms?

Electrons determine the atom's size.

Which of these groups of results would support the hypothesis that PET scans are more likely than physicians' exams to accurately diagnose Alzheimer's disease (AD)?

Group 2 and Group 7

When designing the experiment, the researchers were careful to ensure that the diagnosticians analyzing the PET scans did not know the outcome of the autopsies. Why was this step important for ensuring the validity of the study?

If the diagnosticians knew the autopsy results, it may have influenced their analysis of the PET scans.

Which model most accurately represents the current view of the structure of the atom?

Probability model

Which of these relationships is true of an uncharged atom?

The number of protons is equal to the number of electrons.

Which statement is true of the energy levels of electrons in shells?

The valence shell has higher energy than other occupied shells.

Which of these refers to atoms with the same atomic number but different atomic masses?

These atoms are isotopes.

Which of the following lists of terms is in the correct order of size, going from smallest to largest?

electron, proton, nucleus, atom, molecule

In which scenario given, will the electrons have the highest energy?

electrons in the outer shell of potassium

PET scans are used to diagnose cancer as well as Alzheimer's disease. Cancerous tumors show up as "hot-spots" of high activity because their rapid cell division uses large amounts of sugar. If you were analyzing scans of a patient's brain to determine if there were a cancerous tumor, which of the following would aid in your analysis of the scanned tissue?

previous PET scans of the patient's brain PET scans of healthy brains

Chemists assign atoms to chemical elements by counting their ________.

protons

Dr. Jones says an atom has 3 electrons in the first shell and four electrons in the second shell. Someone should tell Dr. Jones that ...

the first shell shouldn't have 3 electrons.

What determines the types of chemical reactions that an atom participates in?

the number of electrons in the outermost electron shell

What property of an atom determines which element it is?

the number of protons

Two atoms always represent the same element if they have ...

the same number of protons.