integrated science a - unit 3: periodic table and bonding

the alkali metals all have what number of valence electrons?

1

which of the following statements about alkali metals is true?

alkali metals are very reactive.

which answer choice lists the correct chemical name for ain?

aluminum nitride

which answer choice correctly names the element that mendeleev predicted would be discovered and placed in the aluminum column?

gallium (ga)

which of the families can be found in group 17 of the periodic table?

halogens

which of the following statements best describes how moseley's research affected the periodic table?

it became organized by atomic number instead of atomic mass

lesson 12

organizing elements

which answer choice is an example of a correct chemical formula?

al_2o_3

which family of elements can be found in the area marked b?

alkali earth metals

which answer choice is an example of a correct chemical name?

aluminum oxide

read the false statement. atoms of elements with one valence electron form anions in order to meet the octet rule. which answer choice rewords the false statement so it is true?

atoms of elements with five to seven valence electrons form anions in order to meet the octet rule.

lesson 13

bonding

which answer choice correctly describes what will happen to an element with four valence electrons if it engages in a chemical reaction?

it may gain or lose electrons.

what types of elements typically combine to form covalent compounds?

nonmetals

lesson 11

periodic table

which answer choice lists the number and type of elements in a compound in the way that is close to their actual arrangement?

structural formula

which of the following elements could gain stability by forming a covalent bond with one atom of itself? select all that apply.

0.25 of 1 na * h *

which answer choice correctly describes a chemical bond?

a force that holds atoms together in a fixed yet flexible structure

which type of element most likely would be found in the area marked b?

a metalloid

ionic compounds are formed from a combination of _[blank]_ and _[blank]_. which pairs of words correctly complete the statement? select all that apply.

anions; cations metals; nonmetals

examine the false statement. atomic radius increases when moving right across the periods of the periodic table. choose the rewording that makes the statement true.

atomic radius decreases when moving right across the periods of the periodic table

why does the reactivity of elements increase moving left to right on the periodic table?

atoms of elements are closer to filling their valence shell with electrons

a molecule of a covalent compound contains three atoms of fluorine (f) and one atom of boron (b). what is the correct molecular formula and chemical name of the compound described in this statement?

bf_3 : boron trifluoride

how are the elements in the current periodic table arranged?

by atomic number

how did mendeleev organize the elements in the periodic table?

by increasing atomic mass from left to right and top to bottom

which of the following elements are nonmetals? select all that apply.

carbon (c) helium (he)

examine the chemical formula. cs_2 which answer choice lists this compound's chemical name?

carbon disulfide

which elements are part of the halogens group?

chlorine (cl), bromine (br), fluorine (f)

which answer choice correctly describe a trend of valence electrons in the periodic table? select all that apply.

elements in the same group have the same number of valence electrons when moving right across a period, the valence electrons of the main group elements increase by one

which answer choice correctly describes the trend of energy levels from the top of a group to the bottom of a group?

energy levels increase by one when moving down a group

which of the listed properties is the same for the elements beryllium (be), magnesium (mg), and calcium (ca)?

number of valence electrons

which answer choice correctly lists the elements found in period 2 of the periodic table?

oxygen, fluorine, neon

the chemical name for n_2o_5 is dinitrogen _[blank]_. which answer choice correctly completes this statement?

pentoxide

match each bond with the amount of electrons shared in that bond.

single bond : two electrons double bond : four electrons triple bond : six electrons

which of the following statements about metalloids is true?

the properties of metalloids depend on their surrounding environment.

read the false statement. there are 18 periods in the periodic table. which answer choice rewords the false statement so it is true?

there are 18 groups in the periodic table

which of the answer choices lists a true statement about ionic compounds?

they are formed by ions that have opposite charges.

when is an element most likely to be unreactive?

when its valence shell is completely full

in the writing of molecular formulas for covalent compounds, how is more than one atom of an element indicated?

a subscript of the number of atoms is added after that element.

if boron has two energy levels, then how many energy levels do the other two elements have?

aluminum has three energy levels, and gallium has four energy levels

what is the correct molecular formula for a compound that contains one atom of carbon and four atoms of hydrogen?

ch_4

match each label with the correct scientific model or formula.

chemical formula : ch3oh structural formula space-filling model : ball-and-stick model : https://cdstools.flipswitch.com/asset/media/482169

which answer choices correctly describe properties of covalent compounds? select all that apply.

covalent compounds' bonds are not broken apart when placed in water. the electrons in covalent compounds are less mobile than the electrons in ionic compounds.

which answer choice lists the elements in order from the smallest atomic radius to the largest atomic radius?

helium, fluorine, magnesium, potassium

which of the following statements about metalloids is true?

metalloids have properties that fall between those of metals and nonmetals.

which statement best describes how alkali earth metals react with water?

most alkali earth metals react with hot water.

lesson 14

naming and chemical formulas

examine the description. mostly unreactive; a gas which of the families best fits the description?

noble gases

which statements accurately describe nonmetals? select all that apply.

nonmetals fracture easily under pressure. most nonmetals are gases at room temperature.

if the following elements were involved in a chemical reaction, which one would be most likely to form a cation?

potassium (k)

what is the molecular formula and chemical name of the compound?

sif_4 : silicon tetrafluoride

which answer choices correctly describe why the number of known elements more than doubled by 1861? select all that apply.

technological advancements were made communication between scientists increased

which of the following are true statements about chemical formulas? select all that apply.

the number of atoms or ions in a compound are shown as subscripts in the chemical formula. if a compound's ions have a different value, then the chemical formula should have subscripts.

examine the images. https://cdstools.flipswitch.com/asset/media/494600 which statement correctly distinguishes the types of compounds in the images?

the top image is a covalent compound, and the bottom image is an ionic compound.

which statement correctly describes a covalent bond?

the valence electrons are shared between the atoms.

in the writing of ionic chemical formulas, what factor is "crossed over" in the crossover rule?

the value of each ion's charge

which statement correctly describes the reactivity of noble gases, according to the octet rule?

their atoms have eight electrons in their valence shells, so noble gases are very unreactive.

examine the image below. https://cdstools.flipswitch.com/asset/media/488244 which statement correctly describes the periodic trend shown in the image?

valence electrons increase by one when moving left to right across a period.

given the image, how many pairs of electrons do two atoms of oxygen need to share to produce one molecule of o2?

2

which of the following is the lowest common product for the ion values of lithium (li) and oxygen (o)?

2

examine the statements. a - oppositely charged ions attract. b - atoms donate and receive electrons. c - charges of ions balance one another. d - anions and cations are formed. given the statements, what is the correct order of events for the formation of an ionic compound?

b, d, a, c

match the label to the correct description.

ball-and-stick model advantage : it makes it easy to see the number and type of atoms in the compound. ball-and-stick model disadvantage : it falsely depicts chemical bonds as being stiff and inflexible. space-filling model advantage : it shows the physical overlap of the valence shells of the atoms. space-filling model disadvantage : it makes it difficult to estimate bond length and bond angle.

a magnesium (mg) atom gives one electron to two atoms of another element, then it takes on a 2+ charge. the two atoms of the other element each form a 1− charge. as a result, the magnesium ion and the two ions of the other element attract and form an ionic bond. given the scenario, which of the following elements could behave as described and have two of its atoms receive magnesium's electrons?

chlorine (cl)

which answer choice correctly describes the difference between ionic and covalent bonds?

ionic bonds are formed when one atom takes another atom's electrons, while covalent bonds are formed when two atoms share electrons.

which of the answer choices best describes the structure and properties of ionic compounds? select all that apply.

ionic compounds have high melting and boiling points. the structure of ionic compounds resembles a three-dimensional network.

which of the following elements share the same number of energy levels?

potassium (k) and bromine (br)

which answer correctly describe trends regarding reactivity? select all that apply.

reactivity increases when moving down a group reactivity increases when moving across a period

manuel observes a chemical reaction between one atom of silicon and two atoms of oxygen. which answer choice correctly lists the chemical formula of the compound produced by the reaction?

sio_2

which answer choice correctly describes why metals are good conductors of thermal energy?

their atoms have free-floating electrons that easily pass kinetic energy throughout the metal.