Bio Test 2
What can happen to an electron when sunlight hits it?
-It can stay in its original shell. -It can move out to a higher electron shell.
In the compound C6H12O6, how many hydrogen atoms are there?
12
The innermost electron shell of an atom can hold up to _____ electrons.
2
What's the maximum number of electrons that can fit into the first energy level?
2
What is the mass number of an ion with 104 electrons, 158 neutrons, and a +1 charge?
263
An uncharged atom of boron has an atomic number of 5 and an atomic mass of 11. How many protons does boron have?
5. the atomic number is equal to the number of protons
How many individual atoms are found in a molecule of CH4O?
6
In the compound C6H12O6, how many carbon atoms are there?
6
What is the atomic number of an atom that has 6 protons, 6 neutrons, and 6 electrons?
6
What's the maximum number of electrons that can fit into the second energy level?
8
What's the maximum number of electrons that can fit into the third energy level?
8
What happens when two atoms form a chemical bond?
A chemical bond forms when two atoms transfer or share outer electrons to complete their outer shells.
What does the term electron orbital describe?
An electron orbital describes a three-dimensional space where an electron can be found 90% of the time.
Fluorine's atomic number is 9 and its atomic mass is 19. How many neutrons does fluorine have?
Atomic mass is equal to the number of protons plus the number of neutrons (19-9 = 10).
Is neon a "happy" or "unhappy" atom. Briefly explain.
Atoms with complete outer energy levels (two electrons in the first energy level, eight in the next two) are happy. Neon is clearly a happy atom. (10)
Electrons are held in an atom by attraction to what particle or location?
Attraction to the positively charged protons in the nucleus
What's the chemical symbol for carbon?
C
What's the chemical symbol for calcium?
Ca
Nitrogen (N) is more electronegative than hydrogen (H). Which of the following is a correct statement about the atoms in ammonia (NH3)?
Each hydrogen atom has a partial positive charge; the nitrogen atom has a partial negative charge.
Which of the following correctly describes chemical equilibrium?
Forward and reverse reactions continue with no net effect on the concentrations of the reactants and products.
What's the chemical symbol for hydrogen?
H
What's the chemical symbol for potassium?
K
The atomic number of chlorine is 17. The atomic number of magnesium is 12. What is the formula for magnesium chloride?
MgCl2
What's the chemical symbol for nitrogen?
N
Which of these relationships is true of an uncharged atom?
The number of protons is equal to the number of electrons.
Potassium has 19 protons, 19 neutrons, and 19 electrons. Following the Octet Rule for placing electrons in energy levels, which of the following arrangements is correct?
Two electrons in the first energy level, eight in the second, eight in the third, and one in the fourth.
Which of the following bonds can form between atoms of equal electronegativity?
Van der Waals interactions can form between atoms of equal electronegativity.
Which statement about weak bonds is correct?
Weak bonds are transient and easily reversible.
What's the smallest piece of a compound that still has the properties of that compound?
a molecule
An ionic bond involves _____.
an attraction between ions of opposite charge
Atoms with the same number of protons but with different electrical charges _____.
are different ions
the building block of matter is the
atom
The left to right order of elements in the periodic table is based on their ________.
atomic number
Is "C2H2" a structural formula or a chemical formula?
chemical (shows the type of atoms and the # of atoms)
A substance composed of two or more elements that are chemically bonded together
compound
The type of chemical bond where atoms share electrons is called a(n) ________ bond.
covalent
what bond is the one in which electron pairs are shared?
covalent
A(n) ________ has charge but negligible mass, whereas a(n) ________ has mass but no charge.
electron; neutron
In an uncharged atom, the number of protons is equal to the number of
electrons
Negatively charged ____________ are found outside the nucleus.
electrons
A substance composed of only one type of atom is a(n) _______.
element
electrons are found in
energy levels
True or False: In atoms of the same element, the number of neutrons is equal to the number of protons
false
CH4, H2O, NH3, C6H12O6 and all such combinations of chemical symbols and numbers showing the number of atoms of each element in a molecule are called chemical ________
formulas
A ____________ atom with a net positive charge is attracted to an oxygen atom with a net negative charge.
hydrogen
What name is given to the bond between water molecules?
hydrogen
The type of chemical bond where atoms trade electrons is called a (n) _______ bond.
ionic
In salt, what is the nature of the bond between sodium and chlorine?
ionic because ions are attracted to each other
Which of these refers to atoms with the same atomic number but different atomic masses?
isotopes
A(n) _____ refers to two or more atoms held together by covalent bonds.
molecule
The smallest piece of a compound that still has that compound's chemical properties is a
molecule
The electrical charge on a neutron is __________.
neutral
Bonds between two atoms that are equally electronegative are _____.
nonpolar covalent bonds
Most of the mass of the atom is in its ___________.
nucleus
Protons and neutrons are found in the __________.
nucleus
An element's atomic number is indicates its
number of protons
A covalent bond is likely to be polar when ________.
one of the atoms sharing electrons is more electronegative than the other atom
an element is composed of
one type of atom
What's O the symbol for?
oxygen
The _________________________ organizes all of the elements based on their number of protons, and their chemical properties
periodic table
What's P the symbol for?
phosphorus
The electrical charge on a proton is __________.
positive
The two particles found in the atom's nucleus are the
protons and neutrons
What type of bond joins the carbon atom to each of the hydrogen atoms?
single (nonpolar) covalent
What's S the symbol for?
sulfer
Each element is represented by a one or two letter_______.
symbol
What determines the types of chemical reactions that an atom participates in?
the number of electrons in the outermost electron shell
True or False: In uncharged atoms of the same element, the number of protons is equal to the number of electrons.
true