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