HW CHEMICAL BASIS OF BIOLOGY

EXPLAIN HOW ORDINARY TABLE SALT CAN EXEMPLIFY THE THEME OF EMERGENT PROPERTIES

• PURE FORM--TOXIC

• Separately they are elements, when bonded--they are salt

• Cl and Na are 2 different elements with unique properties, those properties are different from salt.

• the elements that make up salt are sodium and chlorine, both of these are different in basic structure, but-- combine to form salt, which is edible.

THE ABOVE QUESTION IS BEST DEFINED AS

• BEING USED AS TRACE ELEMENTS

• ELEMENTS EMERGING AS CHEMICAL COMPOUNDS WITH FIXED RATIOS

• ONE OF 92 COMPOUNDS THAT OCCUR IN NATURE

• HOW SALT IS MADE

In the term trace element, the modifier trace means

• the element is required in very small amounts

• the element can be used as a fluorescent label to trace elements through an organism's metabolism

• the element is very rare on Earth

• the element enhances health but is not essential for the organism's long term survival

• the element passes rapidly through the organism

How many electrons and how many electron levels does a sodium atom have? AND how many electrons are in the valence level?

• 12 and 2 and 1

• 2 and 11 and 22

• 11 and 3 and 1

• 22 and 2 and 1

Chemical Bonding happens

• when a catalyst is present

• at the valence energy shell

• the nature of the elements goes through a physical change

• exclusively in organic chemistry

A strong attraction between atoms is

• only present when the outer levels are touching

• possible only in non-polar ionic bonds

• called electronegative

• usually ionic

Which of these is a correct statement

• Strong covalent bonds make molecules because all energy levels will bond. therefore, extra strength is needed if these kinds of bond form our external and internal structures.

• ionic bonds make molecules by taking electrons from the weaker atoms.

• very reactive elements usually do not form covalent bonds

• ionic bonds will melt in solution

Explain what holds together the ions in a crystal of table salt

• chlorine has a positive charge and sodium has a negative charge so they are highly reactive. Because they are opposite they will attract one another and stabilize.

• there is a strong attraction between oppositely charged ion particles

• a sharing of electrons

• the difference in the structures formed through emergent properties

Water is formed by a(n)

• non-polar covalent bond

• ionic bonding

• polar covalent bond

• hydrogen bond

Choose the best alternative that completes the statement or answers the question.

We all understand that earth has carbon-based life.

In reference to the graphic shown, if life arose on a planet where carbon is absent which element might fill the role of carbon.

• nitrogen

• phosphorus

• aluminum

• silicon