Chapter 2 Flashcards
Define the term- anything that occupies space and has mass
Matter
What are the three states of matter?
Solid, Liquid, and Gas
Define the term- substances that cannot be broken into other substances
Elements
How many elements occur naturally on Earth?
92
How many of those elements are essential to life?
25
Which 4 elements make up 96% of the weight of a human body?
Bonus- name the percent of each
Hydrogen- 9.5%
Nitrogen- 3.3%
Carbon- 18.5%
Oxygen- 65%
What does an iodine deficiency cause?
Goiter
What element has been added to water to decline tooth decay?
Fluoride
What is a compound?
What is salt comprised of?
Is made up up of two elements in a fixed ration
Example- NaCl, Sodium Chloride
What is the smallest unit of matter that still retains properties of an element?
Atom
Define the term- the central core where protons and neutrons are packed tightly.
Nucleus of an atom
What is the atomic number of an element?
number of protons
used to determine which element is present
What is the atomic mass of an element?
The number of protons and neutrons together
Define the term- the mass of a proton and the mass of a neutron are almost identical and are expressed in a unit of measurement.
Dalton
What is equivalent to 1 dalton?
The masses of protons and neutrons
____ are alternate mass forms of an element.
Isotopes
T/F- Isotopes have the same number of electrons and neutrons and DIFFERENT number of protons.
False, Isotopes have different numbers of neutrons NOT protons
What is it called when the nucleus of an element decays which gives off particles and energy?
Radioactive Isotopes
Which of the following is a radioactive isotope?
Carbon-12
Carbon-13
Carbon-14
Carbon-14
What are the 2 uses of radioactive isotopes?
Nuclear Power Plants and PET Scans
By definition, all atoms of carbon have exactly 6 ___, but the number of ____ vary from one isotope to another.
Protons, Neutrons
Define the term- an attraction between 2 atoms resulting from a sharing of outer shell electrons or the presence of opposite chargers on the atoms
Chemical Bonding
Define the term- an atom or molecule that has gained or lost one or more electrons thus acquiring an electrical charge
Ions
How many electrons are gained or lost for the compound NaCl?
Sodium has a +1 charge while chlorine will have a -1 charge
Which ions often have names ending in the suffix “-ide”?
Negatively Charged Ions
Define the term- an attraction between atoms that share one or more pairs of electrons
Typically, form when 2 atoms share one or more pairs of electrons
Covalent Bonds
Define the term- a type of weak chemical bond formed when a partially positive hydrogen atom from one polar molecule is attracted to the partially negative atom in another molecule
Hydrogen Bond
Define the term- a molecule containing an uneven distribution of charge due to the presence of polar covalent bonds ( bonds having opposite charges on opposite ends).
Polar Molecule
Define the term- a process. leading to chemical changes in matter, involving the making and/or breaking of chemical bonds
Chemical Reactions
What type of reaction involves rearranging atoms?
Chemical Reactions
T/F - Atoms can be created and destroyed
False
A starting material in a chemical in a chemical reaction is known as-
Reactant
An ending material in a chemical reaction is known as-
Product
Some people in your study group say they don’t understand what a polar molecule is. You explain a polar molecule is____.
slightly negative at one end and slightly positive at the other end
What is an atom’s inner electron shell filled with?
2 electrons
The bond between the hydrogen atom of one water molecule and the oxygen atom of another water molecule is made possible by?
The polarity of the water molecule
Which of the following is the reactant? Product?
C6H12O6 + 6 O2 → 6 CO2 + 6 H2O
C6H12O6 + 6 O2 are reactants, and 6 CO2 + 6 H2O are products
A solution with a pH of 5 is __________ times more __________ than a solution with a pH of 8.
1,000 … acidic
H2O is an example of a(n) __________.
Compound
Carbon has four electrons in its outermost shell. A single atom of carbon can participate in a maximum of __________ covalent bonds.
4
Cocoa is mixed with hot water to make hot chocolate. The cocoa is the __________, the hot water is the __________, and the resultant hot chocolate is the __________.
solute … solvent … solution
What do cohesion and surface tension have in common with reference to water?
They are both properties related to hydrogen bonding.
Which bond or interaction would be difficult to disrupt when compounds are put into water?
covalent bonds between carbon atoms
If an atom has a charge of +2, which of the following statements must be true?
It has two more protons than electrons.
A substance that increases the hydrogen ion (H1) concentration in a solution.
Acid
Define the term-A chemical substance that resists changes in pH by accepting hydrogen ions from or donating hydrogen ions to solutions.
Buffer
You are making Kool-Aid. You mix the sugar and Kool-Aid into a pitcher of water. Which of the following is a true statement?
The sugar and Kool-Aid are the solutes, the water is the solvent, and the finished mixture is the solution.
What minimizes changes in pH by accepting H+ when they are in excess and donating H+ when they are depleted
Buffers
You put some ice cubes in a glass and fill it to the brim with water. You forget about it for a while, then come back. What would you notice?
The water is at the same height or is slightly lower.
Elements that can exist in different forms and have different masses are termed
Isotopes
T/F Ice is more dense than water
False
How does the cohesion of water relate to the themes of biology?
The cohesion of water is due to the relationship between its structure and function. The molecular structure of water influences how it functions by allowing hydrogen bonds to form and creating a high cohesion.
Bleach is a —— solution and has a high concentration of —— .
basic , OH-
How can radiation be beneficial to humans?
When you expose your body to radiation, it can be used to treat cancer that has metastasized.
Radiation does not have any benefits because it will always cause harm to the cells that are exposed.
Radiation can be used to increase the amount of genetic diversity in a population because it causes mutations.
When given in isolated and calibrated beams, it can be used to treat tumors.
When given in isolated and calibrated beams, it can be used to treat tumors.
Water forms _________ bonds and is _________.
covalent ; polar
You finish filling up a water bottle and place it in the freezer. You come back the next day and notice that ________________.
the bottle has expanded
If you’ve ever burned yourself on a metal pot while waiting for water to boil, you know that water heats up much more slowly than metal. In fact, water has a stronger resistance to temperature change than most other substances.
This property of water is caused by __________.
hydrogen bonding
How is an ionic bond formed?
transfer of valence electrons
How is a covalent bond formed?
by sharing valence electrons
How is a hydrogen bond formed?
By 2 hydrogen atoms joined to 1 oxygen atom by single covalent bonds
How does the hydrogen contribute to the properties of water?
hydrogen bonds stick together making water have a strong property of cohesion
If an atom has a charge of 2+, what must be true?
The atom has 2 more protons than electrons
