Basic Chemistry, Properties of Water, Acids, Bases, and pH
How many electrons are in each orbital?
1st= 2, 2nd = 8, 3rd = 8
What is H2O made of?
2 hydrogen and 1 oxygen
How many electrons would be present in the outer orbital if the atomic number is 16?
6
What is a neutral pH and an example?
7 (water)
ionic bond
A chemical bond resulting from the attraction between oppositely charged ions. One atom lost an electron the other gained an electron
covalent bond
A chemical bond that involves sharing a pair of electrons between atoms in a molecule
surface tension
A measure of how difficult it is to stretch or break the surface of a liquid
high specific heat
A property of water. Water can absorb lots of heat before changing temperature
Element
A pure substance made of only one kind of atom
Adhesion
An attraction between molecules of different substances (water hydrogen bonding with other polar or ionic molecules)
Cohesion
An attraction between molecules of the same substance (water hydrogen bonding with water)
Isotope
Atoms of the same element that have different numbers of neutrons
hydrogen bond
Attraction between a slightly positive hydrogen atom and a slightly negative atom.
Atom
Basic unit of matter
Main elements in living things
CHNOPS (carbon, hydrogen, nitrogen, oxygen, phosphorus, sulfur)
Which molecule has a polar covalent bond?
H2O
When moving away from pH 7, are substances becoming weaker or stronger acids and bases?
Stronger
What are valence electrons?
The electrons in the outermost shell of an atom
net charge
The sum of negative and positive charges.
Why is water more negative near the oxygen atom?
There is an uneven distribution of electrons. Electrons spend more time near the oxygen atom.
What is the benefit of high specific heat capacity?
Water is slow to heat up slow to cool down, moderates temperature changes in in nature
capillary action in plants
a cohesive and adhesive force due to attraction between water and small tubes in the plant.
Acid and Bases
acid = many hydrogen ions, base = many hydroxide ions
ion
atom that has a positive or negative charge
What kind of bond is in a water molecule
covalent bond
The symbol and charge for an electron
e-
Location of an electron in an atom
electron cloud
The chemical behavior of an atoms depends on the ability of a subatomic particle to move. Which one particle does this>
electrons
Where is a hydrogen bond found in water?
from a hydrogen atom of one water molecule to the oxygen atom of another water molecule
What does pH measure?
hydrogen ion concentration
The bond in NaCl
ionic
What is the pH of acid rain?
less than 5.6
What is the pH scale?
measures how acidic or basic a substance is (0-14)
polar molecule
molecule with an unequal distribution of charge, resulting in the molecule having a positive end and a negative end
The symbol and charge for neutron
no charge
location of neutron in an atom
nucleus
location of proton in an atom
nucleus
Which end of the water molecule is slightly negative?
oxygen end
The symbol and charge for a proton
p+
properties of water
polarity, cohesion, adhesion, excellent solvent, solid is less dense than liquid, high specific heat, can be found in nature as a solid, liquid or gas (only naturally occurring substance that is found in all three states)
The atomic mass is calculated by adding
protons and neutrons
What are the three subatomic particles?
protons, neutrons, electrons
What is NaCl
sodium chloride/ table salt
When the outer orbital is filled with electrons it tends to be
stable and nonreactive
Compound
substance formed by the chemical combination of two or more elements in definite proportions
capillary action
the combined force of attraction among water molecules and with the molecules of surrounding materials
Which subatomic particle makes each element unique?
the protons
Molecule
two or more atoms held together by covalent bonds
Ice is less dense than water because
water expands when frozen and ice floats on top of water.
What are buffers?
weak acids or bases that can react with strong acids or bases to prevent sharp, sudden changes in pH
