ch2 Chemical Context

Question 1

element

Answer 1

a substance which cannot be broken down to other substances by chemical reactions

Question 2

compound

Answer 2

substance of 2 or more elements

Question 3

trace elements

Answer 3

elements required by an organism in minute quantities.

Question 4

dalton

Answer 4

unit of measurement for particle mass

Question 5

atomic number

Answer 5

of protons, written in upper left

Question 6

mass number

Answer 6

sum of protons and neutrons, written as superscript left of symbol

Question 7

isotopes

Answer 7

variation of atomic form for an element due to electrons

Question 8

radioactive isotope

Answer 8

unstable isotope in which decay gives off energy and may lead to an elemental change.

Question 9

valence electrons

Answer 9

electrons in the outermost electron shell

Question 10

covalent bond

Answer 10

2 atoms sharing a pair of valence electrons

Question 11

double bond

Answer 11

the sharing of 2 valence electrons (O2)

Question 12

nonpolar covalent bond

Answer 12

a bond in which electrons are shared and their is a balance of polarity (O2)

Question 13

polar covalent bond

Answer 13

a bond in which electrons are shared and the polarity varies (H2O)

Question 14

ionic bond

Answer 14

a bond formed by the polar attraction between positive and negative. electrons are not shared.

Question 15

salts

Answer 15

common compounds formed by ionic bonds

Question 16

hydrogen bond

Answer 16

covalent bond between hydrogen and an electronegative atom (O/N)

Question 17

van der Waals interactions

Answer 17

Weak attractions between molecules or parts of molecules that result from localized charge fluctuations.