Science - Ch. 12, Sec. 1 - Questions

The outermost energy level of an atom is considered to be full if the energy level contains _______ electrons. Because it is full, it is rare for these elements to bond with other elements. This is especially true for the _________ gases (Group _____) because their outer energy level is full.

8 noble 18

True/False: All of the electrons in an atom make chemical bonds.

False

True/False. All substances are made of atoms of one or more of the approximately 100 elements.

True

True/False. When chemical bonding occurs, the properties of the new substances are different from the properties of the original substances.

True

Which element has a full outermost energy level containing only 2 electrons? a. flourine, F b. helium, He c. hydrogen, H d. oxygen, O

b

Which of the following atoms do not usually form bonds? a. calcium b. neon c. hydrogen d. oxygen

b

The atomic number is the number of protons in an element. However, because an atom has no _____________, the atomic number also tells us the number of _____________ in an atom.

charge electrons

An interaction that holds two atoms together is a(n) ___________________.

chemical bond

When _______________ form, electrons are shared, gained, or lost.

chemical bonds

Electrons in an atom are organized in ______________ levels. The first energy level is closest to the nucleus and can hold up to ______ electrons. Electrons will begin filling the second energy level only after the first level is _________. The second energy level can hold up to _______ electrons.

energy 2 full 8

Atoms bond by ____________, _____________, or _________________ electrons to have a filled outermost energy layer.

gaining losing sharing

You can tell the number of valence electrons for some elements by looking at the Periodic Table. Atoms of element in Groups 1&2 have the same number of valence electrons as their ___________ number. Atoms of elements in Groups ______ - _______ have 10 fewer valence electrons than their group number........EXCEPT for ___________ which has only 2 valence electrons.

group 13 18 Helium (HE)

Because atoms and chemical bonds cannot be seen with the unaided eye, the use of __________ helps people discuss the theory of how and why atoms form bonds.

models

Most atoms form bonds using only the electrons in the ____________ energy level. The electrons in the outermost energy level are known as ______________ electrons.

outermost valence

A _________ is an explanation for some phenomenon that is based on observation, experimentation, and reasoning.

theory

An electron in the outermost energy level of an atom is a(n) ____________________.

valence electron