Atomic Structure Flashcards Preview

Honors Biology 1st Semester Exam > Atomic Structure > Flashcards

Flashcards in Atomic Structure Deck (17):
1

Where are electrons found?

The electron cloud

2

How many electrons are in an element

The number of protons, or atomic number

3

Where are protons found?

Nucleus

4

Where are neutrons found?

Nucleus

5

Where is the nucleus located?

Center of atom

6

What is the basic unit of matter?

Atoms

7

Atoms are _______ because they have equal amounts of protons and electrons.

Neutral

8

Which atomic model shows electrons in energy levels around the nucleus?

The Bohr Model

9

How many electrons can the first energy level hold?

2

10

How many electrons can the second energy level hold?

8

11

How many electrons can the third energy level hold?

18

12

What is the current atomic model?

The Electron Cloud Model

13

Electrons in the outer energy shell

Valance electrons

14

Atoms of the same element with different numbers of protons

Isotopes

15

The mass number of an element is ______.

A weighted average based on the abundance of each isotope in nature

16

Name 3 uses for radioactive isotopes.

Radioactive isotopes are useful for establishing the ages of various objects. The half-life of radioactive isotopes is unaffected by any environmental factors, so the isotope acts like an internal clock.

The radiation emitted by some radioactive substances can be used to kill microorganisms on a variety of foodstuffs, which extends the shelf life of these products. Produce such as tomatoes, mushrooms, sprouts, and berries are irradiated with the emissions from cobalt-60 or cesium-137. This exposure kills a lot of the bacteria that cause spoilage, so the produce stays fresh longer. Eggs and some meat, such as beef, pork, and poultry, can also be irradiated. Contrary to the belief of some people, irradiation of food does not make the food itself radioactive.

Smoke detectors

17

What is a radioactive isotope?

Radioactive isotopes or radioisotopes are naturally or artificially created isotopes of chemical elements that have a very unstable nucleus. These products emit rays like alpha, beta and gamma rays. After the nucleus splits, it decays and forms a different atom having different number of protons.