Chemistry Chap 3 Test Review

Write the symbol for each of the following. Determine the number of protons, neutrons, and electrons in each atom. a. a copper atom with a mass of 63 b. a calcium atom with a mass of 40 c. a manganese atom with a mass of 55

-63/29Cu, 29 electrons and protons, 34 neutrons -40/20Ca, 20 protons and electrons, 20 neutrons -55/24Mn, 24 neutrons and electrons, 31 neutrons

Write the symbol for each of the following. a. the beryllium atom that has 5 neutrons b. the chlorine atom that has 20 neutrons c. the lithium atom that has 3 neutrons

9/4Be 37/17Cl 6/3Li

What information is given in a chemical formula?

A chemical formula gives us the types of atoms and the number of each atom in each unit (molecule) of a given compound.

Give the formulas for the compounds that contain the following pairs of ions. a. Ba21 and N32 b. Mg21 and O22 c. Li1 and S22 d. Ca21 and Br2

Ba3N2 MgO Li2S CaBr2

Give the name for each of the given symbols. a.Ba b. Cl c. Si d. F e. N f. Br

Barium Chlorine Silicon Fluorine Nitrogen Bromine

Did Daltons model of the atom include protons, neutrons, and electrons inside the atoms? Explain.

Dalton's model did not include protons, neutrons, and electrons because they were not known at the time.

What are the relationships between the group number on the periodic table and the types of ions formed?

Elements in Group 1 and 2 form 1+ and 2+ ions while Group 7 atoms form anions with 1- charges and Group 6 with 2-.

Show how fluorine forms an ion. Does it form a cation or an anion?

F + e- → F- and it forms a anion

Write the formula for each of the following substances, listing the elements in the order given. a. a molecule containing one hydrogen atom, one nitrogen atom, and three oxygen atoms b. a molecule containing three carbon atoms and eight hydrogen atoms c. a molecule containing one nitrogen atom and three hydrogen atoms

HNO3 H2O2 C3H8 CO NH3 O3

Which elements exist naturally as diatomic molecules? Write their formula.

Hydrogen (H2); Oxygen (O2); Fluorine (F2); Bromine (Br2); Nitrogen (N2); Iodine (I2); Chlorine (Cl2), are elements that are naturally diatomic molecules.

Give the symbol for each of the given elements. a.iron b. zinc c. hydrogen d. lithium e. copper f. neon

Iron: Fe Zinc: Zn Hydrogen: H Lithium: Li Copper: Cu Neon: Ne

Why does an atom have a net zero charge?

It is because there is an equal number of electrons and protons.

What evidence do we have that convinces us that sodium chloride is an ionic compound?

It is not malleable or ductile, it has a high melting point, and it does not conduct electricity as a solid.

To what does the term periodic in periodic table refer?

It refers to the repetitive pattern of chemical activity on the periodic table.

Show how lithium forms an ion. Does it form a cation or an anion?

Li+ + e- → Li and it forms a cation

What does the term noble mean when referring to noble metals and noble gases?

Nobel refers to how these certain gases and metals are relatively reactive or inert.

How was dalton able to predict the formation of multiple compounds between the elements?

Since Dalton thought of compounds as combinations of atoms of one element with atoms of another element, he predicted that compounds could be made of different amounts of the same elements. Examples include CO and CO2

What are the main ideas of Daltons atomic model?

The main ideas of his theory are: -Elements are made of tiny particles called atoms -All atoms of a given element are identical -The atoms of a given element are different from those of any other elements -Atoms of one element can combine with atoms of other elements to form compounds. A given compound always has the same relative numbers and types of atoms. -Atoms are indivisible in chemical processes. That is, atoms are not created or destroyed in chemical reactions. A chemical reaction simply changes the way the atoms are grouped together.

What observations led Dalton to the purpose his model for the atom?

The observations that led dalton to propose his atomic theory included most natural materials are mixtures of pure substances, a given compound always contains the same proportions (by mass) of the elements, and pure compounds are either elements or compounds.

What does the "stair-step" line on the periodic table tell you?

The stair-step line is the line between metals and nonmetals on the periodic table. Elements to the left are metals and to the right are nonmetals

How many of the top ten elements in the earth's crust, ocean, and the atmosphere? What are these elements

There are six elements which include calcium, sodium, hydrogen, magnesium, and potassium.

Which elements are gases at 25°C? Write their formulas.

These gaseous elements are Hydrogen (H2); Oxygen (O2); Fluorine (F2); Chlorine (Cl2), Helium (He); Neon (Ne); Argon (Ar); Krypton (Kr), Xenon (Xe); and Radon (Rn).

Why are the elements in vertical groups on the periodic table called "families"?

They are called families because the properties of the elements in the vertical columns are alike. This is similar to a family because a family usually has similar characteristics.

How is Thompson's model of the atom different from Dalton's model of the atom.

Thompsons model of the atom shows positive and negative charges uniformly distributed throughout the atom. He also made the neutral atoms have the same amount of positive and negative charge. Dalton made the atoms have no charge and are invisible.

In two isotopes of the same element, which of the following would be the same, and which would be different. -atomic number -number of protons -number of neutrons -number of electrons -element symbol

Two things that are different in two isotopes are the mass and number of neutrons. The things that are the same are the number of protons and electrons, the atomic number, and the element symbol.

What caused Rutherford to propose a revised model of the atom? How is the Rutherford model different from the previous model?

When Rutherford could not understand how an alpha particle could be deflected when passing through a sheet of gold foil, he decided to reinvent the model of the atom. Old models of the atom revolved around having the same density throughout. Rutherford focused on the nucleus of the atom. The nucleus of the atom is located in the center and contains the most mass. The rest of the atom contained nothing else, just empty space and the atom was believed to be aproximently uniform density.

Give 4 different chemical meanings for the word element and give an example for each

a singe atom