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BJU Physical Science
Study questions for Chap 18
Question | Answer |
---|---|
Atoms are usually most stable when they have a full 8 electrons in their valence level fulfills this | octet rule |
Large organic molecules that have unique properties | macromolecules |
What factors affect a molecules shape? | the number of bonds an atom forms affects the molecules shape |
Nonmetals with uneven electron negativities form what type of bonds? | polar covalent bonds |
Ions in a solution are called | electrolytes |
element that naturally occurs as 2 identical, bonded atoms or any particle consisting of 2 atoms | Diatomic element |
Why do atoms bond? | to obey the octet rule, to become more stable and follow the second law of thermodynamics |
How do electrolytes conduct electrical currents? | they have to be in a solution, makes them an excellent conductor of electricity |
What determines bond strength and bond type? | the difference in electronegativity of the elements |
Molecules that are partially charged on each end | polar diatomic molecules |
Which is stronger; ionic or covalent bonds? | ionic |
This group of elements have only one or two valence electrons | metals |
Which type of bonds DO NOT follow the octet rule? | metallic bonds |
List the properties of ionic compounds. | they can form bonds with metals and nonmetals |
An unbonded atom's ability to attract and hold electrons is its | electron affinity |
a bonded atom's ability to attract and hold electrons is its | electronegativity |
three-dimensional arrangement of atoms or ions | crystal lattice |
Electrons in metallic compounds are | are free |
How do the covalent compounds in our bodies show God's design | it shows that these things could only happen because he created us |
a molecule containing just 2 elements | Diatomic molecule |
Three properties of metal are | malleability, luster, thermal and electrical conductivity, ductility |
Metal bonds sharing free electrons | Free electron theory |
contains carbon and has at least one hydrogen atom | Organic compound. |
two non-metals share electrons to form bonds | Covalent Bonds |
low polarity, low melting and boiling point and liquid or gaseous at room temperature is what type of bond | Covalent Bonds |
formed between a metal and a non-metal. Non-metals are "stronger" than the metal and can get electrons very easily from the metal | Ionic Bonds |
high polarity, high melting and boiling point and solid at room temperature is what type of bond | Ionic Bonds |
Hydrogen chloride (HCI), poisonous gas, molecular is covalent or ionic or metallic? | covalent |
Calcium iodide (Cal2), yellowish white solid, high melting point, soluble in water is covalent or ionic or metallic? | ionic |
Ytterbium (Yb), silvery lustrous solid, ductile, malleable, high melting point is covalent or ionic or metallic? | metallic |
Bromine (Br), reddish brown liquid, electrical insulator, molecular is covalent or ionic or metallic? | covalent |
Magnesium oxide (MgO), powdery white solid, high melting point, electrical insulator is covalent or ionic or metallic? | ionic |
Aluminum (Al), silver white luster, ductile, good electrical conductor, insoluble | metallic |
what class of elements form a covalent compounds | nonmetals |
The smallest ratio of elements in an ionic compound that describes its chemical composition | formula unit |
form when each atom must share 3 electrons to complete it's octet | triple bond |
shares 2 pairs of electrons to form a double covalent bond | double bond |
diatomic elements form bonds with no polarity | nonpolar bonds |
metal atoms share electrons | metallic bond |
consist of covalently bonded molecules | covalent compounds |
pair of dots between the symbols that identifies a covalent bond | Lewis Structure (electron dot notation) |
What is the difference between eltronegativity and electron affinity? | electronegativity is a bonded atom's ability to attract and hold electrons is its |
What are two main ways atoms aquire a full outer energy level | sharing electrons and when atoms gain or lose electrons to gain a full octet |
Name and describe the model that accounts for metallic bonding | the electron sea theory (free electron theory) electrons are shared among all the other bonded atoms in the element |
How is electron dot notation notations useful for predicting the number of covalent bonds a nonmetal can form? | the number of unpaired dots is the number of covalent bonds the atom can form with other atoms |
What are the beneficial properties of covalent compounds as the main components of living organisms? | light, flexible, strong and do not easily dissolve |
Difference between electonegativity and electron affinity? | electronegativity varies it's place on the periodic table and its atomic number ;electron affinity is a measure of how well it attracts and holds electrons |
Why are covalent bonds between different elements always polar? | They have different electronegativities. |
what determines the shape of simple molecules | the number of bonds an atom forms |
how do metal atoms in the solids state most often arrange themselves | in a hexagonal closed package |