Chem - Chapter 2

Group 1A

alkali metals

Group 2A

alkaline earth metals

The number of protons = the number of electrons

atomic number

1. Zinc can be uniformly mixed in differing amounts in copper to an alloy called brass. Brass is an examples of which of the following? A. compounds B. elements C. a homogeneous mixture D. a heterogeneous mixture

c. A homogeneous Mixture

elements united in fixed ratios

compounds

the outermost incomplete shell of an atom

definition of valence shell

nonuniform composition

heterogeneous matter

uniform composition throughout

homogeneous Matter

anything that occupies space and has mass

matter

Have some properties of metals and nonmetals

metalloids

A combination of two or more pure substances

mixture

Group 8A

noble gases

16. Which of the following correctly represents the electronic configuration of Argon (Ar)? A. 1s22s22p63s23p6 B. 1s22s22p63s23px23py13pz1 C. [Ne]3s23p4 D. All of the above

A. 1s22s22p63s23p6

18. Atoms of which of the following elements are smallest? A. Al B. Mg C. Na D. They are all the same size

A. Al

12. Which element is represented by Period 3, Group 7A (17)? A. Cl (chlorine) B. O (oxygen) C. S (sulfur) D. P (phosphorus)

A. Cl (chlorine)

7. What is the element that is made up of 27 protons, 33 neutrons and 27 electrons? A. Cobelt (Co) B. Arsenic (As) C. Neodymium (Nd) D. Francium (Fr)

A. Cobelt (Co)

4. Which of the following correctly describes a proton? A. on the scale of subatomic particles it is massive and has a +1 charge B. on the scale of subatomic particles it is massive and has a -1 charge C. on the scale of subatomic particles it is light and has a +1 charge D. on the scale of subatomic particles it is light and has a -1 charge

A. On the scale of subatomic particles it is massive and has a 1+ charge.

The weighted average of the masses (in amu) of the naturally occurring isotopes of an element.

Atomic Weight

15. Select the correct e- energy level arrangement for aluminum (Al). A. 2, 8, 1 B. 2, 8, 3 C. 2, 8, 5 D. 2, 8, 7

B. 2, 8, 3

14. Carbon (C) has _____ valence electrons A. 2 B. 4 C. 6 D. 8

B. 4

6. What is the mass number of an atom which is made up of 38 protons, 52 neutrons and 38 electrons? A. 128 B. 90 C. 52 D. 38

B. 90

8. Strontium-90 is a radioactive isotope which is particularly hazardous. Which of the following statements is true about an atom of strontium-90? A. It contains 38 neutrons. B. It contains 38 protons. C. It contains 90 neutrons. D. It contains 90 protons.

B. It contains 38 protons.

11. The properties of ductility, malleability, ability to conduct heat and electricity are characteristics of what type of material? A. all elements B. metallic elements. C. metalloid elements D. nonmetallic elements

B. Metallic Elements

2. Ammonium nitrate is a component of both fertilizers and explosives. Ammonium nitrate has nitrogen, hydrogen and oxygen atoms in the ratio 2:4:3. What is the correct formula for ammonium nitrate? A. N1H2O1.5 B. N2H4O3 C. N4H8O6 D. All of the above

B. N2H4O3

5. How many protons are in the nucleus of the chlorine (Cl) atom? A). 11 B). 12 C). 17 D). 25

C. 17

10. Which of the following contains only transition metals? A. Ca, Cr, Fe, Ni B. V, W, Xe, Zr C. Cr, Mn, Ni, Pt D. None of the above

C. Cr, Mn, Ni, Pt

13. Group 7A elements: F, Cl, Br, and I are _____. A. alkali metals B. alkaline earth metals C. halogens D. noble gases

C. Halogens

19. Which of the following is true of the ionization energy of the elements? A. Ionization energy generally decreases as we move left to right and decreases as we move top to bottom in the periodic table. B. Ionization energy generally decreases as we move left to right and increases as we move top to bottom in the periodic table. C. Ionization energy generally increases as we move left to right and decreases as we move top to bottom in the periodic table. D. Ionization energy generally increases as we move left to right and increases as we move top to bottom in the periodic table.

C. Ionization energy generally increases as we move left to right and decreases as we move top to bottom in the periodic table.

17. Which of the following is true when comparing two electrons which are in different shells of an atom? A. The electron in the higher numbered shell is closer to the nucleus and is easier to remove. B. The electron in the higher numbered shell is closer to the nucleus and is harder to remove. C. The electron in the higher numbered shell is further from the nucleus and is easier to remove. D. The electron in the higher numbered shell is further from the nucleus and is harder to remove.

C. The electron in the higher numbered shell is further from the nucleus and is easier to remove.

A pure substance that is made up of two or more elements in a fixed ratio by mass. Ex: Sodium chloride (NaCl) or table salt; water (H2O)

Compound

3. A number of elements occur naturally as diatomic molecules under normal atmospheric conditions. Which of the following does occur naturally as a diatomic molecule? A. oxygen B. hydrogen C. nitrogen D. All of the above

D. All of the Above

20. The ionization energy is the energy needed to remove the least tightly bound electron from an atom in the gaseous (g) state. Which one of the following elements has the LOWEST ionization energy? A. Br B. Cl C. F D. I

D. I

9. Which of the following is true of the atomic weight of an element? A. It is the weight of heaviest isotope. B. It is the weight lightest isotope. C. It is the weight of the most abundant isotope. D. It is a weighted average obtained from the weights and abundances of the isotopes.

D. It is a weighted average obtained from the weights and abundances of the isotopes

All atoms of the same element have the same chemical properties. Atoms of different have different properties.

Dalton's Atomic Theory

Tells us the ratio of its constituent elements and identifies each element by its atomic symbol.

Formula of a compound

Group 7a

Halogens

Fixed composition; cannot be further purified

pure substances

The arrangement of electrons in the extranuclear space.

Electron COnfigration

A pure substance that consists of identical atom; the building blocks of matter. Symbols consist of one or two letters.

Element

Cannot be subdivided by chemical or physical means

Elements

The energy needed to remove a valence electron from an atom because electrons are held by their attraction to the nucleus.

Ionization Energy

atoms with the same number of protons but different number of neutrons

Isotopes

The number of protons + the number of neutrons

Mass number

Solids, ductile, malleable, form alloys, give up electrons and form cations.

Metals

Example of formula of a compound

Mg : F = 1:2 or H : Cl: O = 1: 1: 4

A combination of two or more pure substances, that may be present in any mass ratio. Homogenous or Heterogeneous. Ex: (Air: 78% N2; 21% O2)

Mixture

do not conduct electricity, accept electrons and form anions, mostly lie on right side expect for hydrogen

Nonmentals

number of valence electrons =

The group number

Any compound is always made up of elements in the same proportion by mass

The law of Constant Composition

1. Na: Cl: O= 1:1:3 = 2. Al: F = 1:3=

1. NaClO3 2.AlF3

an electron in a valence shell The symbol of the element represents the nucleus and filled sheets.

Valence electron