Chapter 2 Biology 110

element

substances that can not be broken down into simpler substances by ordinary chemical means

Electrons

when atoms form bonds, they share or exchange

Single

which covalent bond involves only 2 electrons ( 1 pair)

Hydrogen- very electronegative

which of the following elements is mismatched with its properties or function.

1000; acidic

A pH of 4 is ___ times more ___ than a pH of 7

slightly acidic

A solution having a pH of 6 would be

Adhesion and cohesion

A stalk of celery is placed in a solution of blue colored dye. After on hour, the leaves have blue fluid in their veins. which property of water is being demonstrated?

Acidic

A substance containing more H+ and less OH- would be

Cannot be broken into simpler substances by chemical reactions

An element is defined as a substance that

Involves only valence electrons

Any chemical interaction between atoms:

one

Chlorine has seven electrons in its valence shell. The number of electrons it must gain to complete its valence shell is:

non polar

Covalently bonded atoms that share electrons equally are.

A single covalent bond

H-H

Oxygen, Hydrogen

In a water molecule, because oxygen is more electronegative than hydrogen, the shared electrons are more commonly found around the ____ nucleus than the _____ nucleus

They must have a partial negative charge

In living things, hydrogen bonds typically form between hydrogen and nitrogen or hydrogen and oxygen. What property must oxygen or nitrogen have for this bond to occur?

Sodium donates on electron to chlorine

In the formation of common table salt, sodium and chlorine interact because

Neutrons only

Isotopes differ from each other with respect to the number of:

Number of valence electrons

The chemical reactivity of an atom is determined most directly by the:

Hydrogen bonds

The cohesiveness between water molecules is due largely to:

Hydrogen and oxygen share an electron pair.

The covalent bond between a hydrogen atom and the oxygen atom in water is formed when;

An ion has an unequal number of protons and electrons, while an atom has an equal number

The difference between an electrically neutral atom and an ion is that:

Determines the chemical properties of the atom

The outer electron energy level of an atom

Protons

The particular type of element is determined by the number of

Non polar covalent bond and polar covalent bond

This bond is the result of two atoms sharing electrons in such a way that each atom has a full valence shell

acting as a buffer

When a small amount of hydrochloric acid is added to a solution of Na2HPO4, the pH of the solution does not change markedly. The pH also does not change drastically when a small amount of sodium hydroxide (NaOH) is added to this same solution. Based these observations, the compound Na2HPO4 is

C6H12O6 and 6 O2

Which of the following choices correctly identifies a reactant in the following chemical equation

S

Which of the following elements is NOT responsible for a significant portion of the mass of living organisms

They each have 6 protons

Which of the following facts allows you to determine that atom A and atom B are isotopes of the same element

Compared to other substances, little energy is required to raised or lower the temperature of water

Which of the following statements is not correct?