SC100 Final Exam

What would you expect the element barium to do when it forms a chemical bond?

Give up 2 electrons

The ice cubes in your water glass float because

the hydrogen "bonds" between water molecules in the ice create an open, less dense structure

Consider the following two substances: (1) strontium bromide (SrBr2) and (2) sulfur tetrafluoride (SF4). (The 2 and 4 should be subscripted, but this can't be done here!) What is the type of bonding found in (1) and (2) respectively?

ionic, covalent

Rank the following in order of decreasing pH: blood, a solution of SoftSoap, wine

Blood, soft-soap, wine

Why do electrons in atoms rearrange to form chemical bonds?

In order to create stable atoms with outer electron shells that are completely filled with electrons

If you want to quickly determine how many valence electrons a neutral atom of an element has

you note what column of the Periodic Table it is in

When gasoline, candle wax, or natural gas burn, the products are

carbon dioxide and water vapor

Which one of the following is not true about polymers?

Many polymers are natural in origin.

Intermolecular forces hold repeating units together in a polymer.

Polymers are comprised of repeating units.

DNA is an example of a polymer.

Intermolecular forces hold repeating units together in a polymer

In the demonstration with the aluminum foil strip copper +2 ion in the blue solution was converted to copper metal. This represents what chemical process?

oxidation-reduction

Which of the following processes is exothermic?

sublimation

evaporation

freezing

freezing

How do glucose and sucrose differ?

Glucose contains one sugar ring, while sucrose contains two

Why do we call the molecules of life "biological polymers"

They are modular, made from smaller units

Amino acids are to proteins as

glucose is to cellulose

Organic molecules

have a framework consisting of carbon atoms

What health problem is associated with the consumption of saturated fats?

Heart disease

Trans fatty acids

Are found in large amounts in butter

May increase the risk of heart disease

Are produced in fats during hydrogenation

All the above

B and C only

B and C only

What part of a phospholipid is hydrophilic?

The phosphate group ("head")

Why does a saltine cracker taste sweet after it has been in your mouth for a bit?

An enzyme in your saliva can break down starch into glucose

What is the health advantage to eating tofu and rice together, as discussed in class?

Eating both together insures that all eight essential amino acids are consumed

A type of molecule that accelerates a chemical reaction in living systems and is recycled in the process is known as

an enzyme

Atoms bind together in chemical reactions bythe

rearrangement of electrons

What did Dimitri Mendeleev study?

the regularity or periodicityin the properties of theelements

Each element is assigned an ____________________ which is __________________________ in an atom of the element

atomic number, equal to the number ofprotons

________________________ are _________________________ in the periodic table in order of_______________

Elements, arranged, increasing atomic number

_______________ are found on the ______________________ and __________________ on the __________________

Metals, left side, non-metals, right side

__________________________ in the _______________________ have very ___________________________

Elements, same vertical column, similar chemical properties

The pattern of elements in the Periodic Table reflects the arrangement of electrons around the

nucleus

In an ______________ are _______________ into

Electrons, arranged, concentric shells

How many electrons does hydrogen have in the first shell?

one

How many electrons does helium have in the first shell and how does it fill the first shell?

two, completely fills

Where is the third electron of lithium placed?

in the 2nd electron shell

________________ in the _______________ of the periodic table possess the __________________ and thus have __________________

Elements, same column, same number of outer (valence) electrons, similar chemical properties

For columns ____________________, the _______________ gives the ________________________

1A through 8A, column number, number of outer (valence) electrons

What do elements in the same column of the periodic table contain?

same number of outer electrons