Science Chapter 5

Which element is less reactive, an element whose atoms have seven valence electrons or an element whose atoms have eight valence electrons? Explain.

An elements whose atoms have eight valence electrons is less reactive than an element whose atoms have seven electrons because the former has completed its octet. The latter just needs one more electron, which makes it highly reactive.

The formula of Sulfuric Acid is H2SO4. How many atoms of hydrogen, sulfur, and oxygen are in one molecule of sulfuric acid?

Hydrogen: 2 Sulfur: 1 Oxygen: 4

How is the formation of an ionic bond different from the formation of a covalent bond?

Ionic bonds are formed between two oppositely charged ions (usually a positively charged metal and a negatively charged nonmetal), and their force of an attraction has to do with the attraction between negative and positively shared atoms. Covalent bonds are generally two nonmetals that share electrons between them.

Why do ionic compounds generally have high melting points?

Ionic compounds have high melting points because the attraction between their atoms (that make up the bond) are strong. Therefore, it takes a great amount of energy to break apart those ionic bonds.

When atoms react, they form a chemical bond, which is...

a force of attraction that holds two atoms together as a result of rearrangement of electrons.

Pure metals tend to be weaker and more reactive than an alloy, which is a...

a mixture of two or more elements, where at least one is a metal.

Valence electrons in an atom are those that are..

held most loosely.

When an atom loses or gains electrons, it become a(n)...

ion.

The metal atoms in stainless steal are held together by...

metallic bonds.

Polyatomic ions such as ammonium ions (NH4-) and nitrate ions (NO3-) are ions that consist of...

more than one atom.

The formulas N2, H2O, and CO2 all represent molecules, which are defined as...

neutral groups of atoms formed by covalent bonds.

A covalent bond in which electrons are shared unequally is a...

polar bond.

Magnesium chloride is an example of an ionic compound composed of...

two oppositely charged ions.

An electron dot diagram shows an atom's number of...

valence electrons.