science

Ionic compounds...

-are brittle - have high melting points -are good conductors of electricity in their liquid state

K-40. How many electrons does it have?

19

If an atom has 17 protons and 25 neutrons, the arrangement of its electrons in its 1st, 2nd, and 3rd energy levels would be

2-8-7

How many valence electrons does a silicon atom have?

4

How many oxygen atoms are present in the compound called magnesium chlorate?

6

How many hydrogen atoms are present in one molecule of ammonium acetate, NH4C2H3O2?

7

How many electrons are needed in the outer energy levels of most atoms for the atom to be chemically stable?

8

What is the total number of atoms in the compound Ca(ClO3)2?

9

Identify a physical property that might be used to tell whether a compound is ionic or covalent. Explain why this physical property is a good indicator.

A physical property that would be used to determine whether its a ionic or covalent would be melting point and conductivity.

What ionic compound would you expect to form between aluminum and sulfur?

Al2S3

Beryllium, Be, and chlorine, Cl, form a binary ionic compound with a one-to-two ratio of beryllium ions to chloride ions. The formula for the compound is

BeCl2

Which of the following compounds is molecular?

CCl4

Which statement about metals is true?

Electrons in a metal lattice are free to move.

if gallium ions have a charge of +3 and sulfur ions have -2 charge, the compound gallium sulfide is Select one:

Ga2S3

Which statement best describes the properties of sodium chloride?

Liquid sodium chloride is a good conductor of electric current.

What ionic compound would you expect to form between magnesium and oxygen?

MgO

Which of the following formulas represents a compound whose molecules contain a triple bond?

N=N

Which of the following compounds does NOT contain molecules?

NaCl

Is elemental sodium commonly found in the foods we eat?

No. They are the sodium ions that are in an ionic compound with chlorine.

Four students are studying for a chemistry test and are trying to understand the difference between ionic and covalent bonds. Each student writes his/her own explanation of the difference between ionic and covalent bonds and shares it with the group. Which student's explanation is the most accurate?

Student 3. An ionic bond occurs when two substances react to form a product in which one of the atoms involved in the ionic bond donates its electrons to the other atom in the ionic bond. This results in positively and negatively charged atoms. A covalent bond occurs when two substances react to form a product in which the atoms involved in the covalent bond share electrons.

Which group of elements is the most stable? Explain.

The group of elements that are the most stable are the Nobel gasses because they have 8 valence electrons

Why do the noble gases NOT form compounds readily?

Their outer energy levels are completely filled with electrons

Which of the following statements correctly describes the substance with the formula KI?

There is a one-to-one ratio of potassium ions to iodide ions.

Typically, atoms gain or lose electrons to achieve

a stable electron configuration.

Lithium and chlorine atoms will form...

an ionic bond

A positively charged ion attracts a/an...

anion

n an ionic compound, the attractions between cations and__________hold the compound together.

anions

The elements that make up a compound and the exact number of atoms of each element in a unit of the compound can be shown in a ____.

chemical formula

A chemical bond that occurs when atoms share electrons is a(n) ____ bond.

covalent

Compound X has a melting point of -78°C. It does not conduct electricity and is not soluble in water in its liquid state. What type of compound do you suspect it may be?

covalent

What type of bond would you expect between two atoms of chlorine?

covalent

a certain compound is a gas at room temperature. This compound is most likely...

covalent

You see a structural formula in which the symbols for elements are connected by a long dash. You can assume that the chemical bonds in the compound are

covelent

What kind of chemical bond is formed when an equal exchange of electrons occurs?

diatomic molecule

Ionic compounds are always...

electrically neutral

In a polar covalent bond,

electrons are not shared equally between atoms.

What elements tend to form ionic compounds?

elements found on opposite sides of the periodic table

Because a water molecule has a slight positive charge at one end and a slight negative charge at the other end, it is a nonpolar molecule.

false

Particles formed from the covalent bonding of atoms are called ions.

false

The chlorine atoms in hydrogen chloride have a stronger attraction for the electrons than the hydrogen atoms do. The hydrogen chloride molecule is therefore a nonpolar covalent molecule.

false

The formula SO42- stands for ammonium.

false

The properties of a compound are the same as the properties of the elements making up the compound.

false

When an atom gains or loses electrons, the charged particle that results is called a molecule.

false

Alkali metals, alkaline earth metals, and aluminum all form ions with positive charges equal to the

group number

Which of the following groups contain three elements with stable electron configurations?

helium, xenon, neon

What type of bond would you expect between a calcium atom and a chlorine atom?

ionic

The name iron(II) indicates that a compound contains

iron ions with a 2+ charge

The water molecule H2O is polar because it contains two polar single bonds and

its molecule has a bent shape

Fluorine, F, forms a binary ionic compound with lithium, Li. What is the name of this compound?

lithium fluoride

Write the "traditional" name for: HgO

mercuric oxide

Which type of element would be the most likely to conduct electricity very well

metal

How are ionic compounds formed

metals giving electrons to nonmetals Correct

What is the "stock" name for Ni(NO3)2?

nickel (II) nitrate

What is the "stock" name for: Ni(OH)4

nickel (IV) hydroxide

After reading "Penguins and Polar Bears" and inspecting the picture below...What type molecule do you think CO2 is?

non-polar covalent

What type of chemical bond would you expect between two neon atoms?

none because neon is a noble gas

How are covalent compounds formed?

nonmetals sharing electrons

What does the atomic number stand for?

number of protons

The statement that atoms tend to gain, lose, or share electrons in order to acquire a full set of valence electrons is known as the...

octet rule

Water has a higher boiling point than expected because

of the strong attractions between polar water molecules.

ow many additional electrons can a fluorine atom attract?

one

The outer shells of two atoms that are covalently bonded

overlap

The ____ tells you how many electrons an atom must gain, lose, or share to become stable.

oxidation number

group of covalently bonded atoms that acts together as one charged atom is a ____.

polyatomic ion

A cation is a/an...

positively charged

If an atom has a stable "octet" of electrons, this means that its _________are filled with electrons.

s and p orbitals

In a chemical formula, the number of each type of atom in the compound is shown by numbers called ____.

subscripts

The oxidation number of an atom is shown with a ____.

superscript

Which of the following is a typical property of an ionic compound?

tendency to shatter when struck

Electronegativity is...

the ability of an atom to attract electrons

Which phrase best describes a metallic bond?

the attraction between a metal cation and a shared pool of electrons

HOFBrINCl is...

the list of diatomic atoms

In the compound MgCl2, the subscript 2 indicates that

there are two chloride ions for each magnesium ion.

Metallic bonding is similar to ionic bonding because

there is an attraction between positively charged and negatively charged particles.

The formation of an ionic bond involves the

transfer of electrons.

The elements most likely to form more than one type of ion are the

transition metals

A strong chemical reaction is most likely to occur between...

two ionic solids that have been dissolved in water

n the name carbon dioxide, the prefix of the second word indicates that a molecule of carbon dioxide contains

two oxygen atoms

Which of these atoms has the most mass?

uranium

In an electron dot diagram, each dot represents a(an

valence electrons

Because water molecules are polar and carbon dioxide molecules are nonpolar,

water has a higher boiling point than carbon dioxide does

A student is tutoring another on how to write the formula for binary compounds. The best explanation of formula writing when given the name of the compound is to

write the symbol for the positively charged atom first and the symbol for the negatively charged atom second. Criss-cross the oxidation numbers of the two elements and write as subscripts following the each chemical symbol

In ionic compounds, the sum of the charges of all the cations and anions must be

zero

The sum of the oxidation numbers in a neutral compound is always ____.

zero