Basic Chemistry

How many hydrogen atoms will a single carbon atom bond with to form a stable molecule?

4-Carbon has four electrons in its valence (outermost) electron shell. Therefore, it will form covalent bonds with four hydrogen atoms. The four electrons contributed by the hydrogen atoms will fill the valence shell of carbon.

Positively charged subatomic particle

proton

Negatively charged subatomic particle

Electron

The four elements that make up about 96% of body weight are

Oxygen, carbon, hydrogen and nitrogen

Salts are always

ionic compounds

An atom with an atomic number of 10 and a mass number of 24 would have

14 neutrons

Amino acids joining together to make a peptide is a good example of a(n)

Synthesis

Neutral subatomic particle

neutron

An atom with 3 electrons in its outermost (valence) shell may have a total of ________ electrons altogether

13

Atom X has 17 protons. How many electrons are in its valence shell (outermost energy level)?

7

Smallest particle of an element that retains its properties

atom

What is the most significant factor in the formation of a covalent bond?

the sharing of electron pairs between two atoms; Covalent bonds are formed by the sharing of electrons between two reactive atoms

Is a function of, and varies with, gravity

weight

Calcium's atomic number is 20. It forms ions with 18 electrons. What is the electrical charge of a calcium ion?

+2; With atomic number 20, calcium atoms have 20 positive protons, and the ion has only 18 electrons, which means the net charge is +2. Calcium ions are essential for muscle contractions, nerve impulses, and bone maintenance

A chemical reaction in which bonds are created is usually associated with

Consumption of energy

If atom X has an atomic number of 74 it would have which of the following?

74 Protons

An atom of oxygen has an atomic number of 8 and a mass number of 18. How many of each type of subatomic particle does it contain?

8 protons, 8 electrons, and 10 neutrons

After the transfer of the electron, sodium will form an ion with

A charge of +1; If sodium loses an electron, it will be positively charged. Although not shown explicitly in the figure, the element sodium contains 11 protons within its nucleus. If sodium forms a cation containing 10 electrons, it will have a charge of +1

Which of the following correctly ranks the types of chemical bonds, in order, from strongest to weakest

Covalent, ionic, hydrogen ; In covalent bonds, electrons are shared between atoms; in ionic bonds electrons are lost or gained; but hydrogen bonds are not true chemical bonds—they are weak attractions due to slight electrical imbalances. No electrons are directly involved

Which of the following is not produced through chemical bonding?

Atoms ; Atoms react through chemical bonding to form larger structures. Chemical bonding begins with atoms; it does not produce them. All of the structures that we cover in A&P are made from atoms through chemical bonding

. In a covalent bond

Atoms share one or more pairs of electrons; In covalent bonds, atoms share ("co") their valence electrons ("valent"). These bonds are strong because to maintain stability the atoms must stay close enough together to continue sharing their electrons

Which of the following is an example of a suspension?

Blood

Represented by the flow of charged particles along a conductor, or the flow of ions across a membrane.

Electrical energy

The three atoms shown represent three unique

Elements ; The three atoms each contain different numbers of protons and are therefore unique elements

Although a man who weighs 175 pounds on Earth would be lighter on the moon and heavier on Jupiter,this _______would not be different

Energy

In a solution, the solute is the substance present in the greatest amount.

False; In a solution, the solute is the substance present in lesser amounts. There may be many solutes.

Nonpolar molecules are the result of unequal electron pair sharing

False; Polar molecules are the result of unequal electron pair sharing. Nonpolar molecules are electrically balanced because of the equal sharing of electrons between the atoms of the molecules.

Atomic weight is equal to the number of protons and neutrons in the nucleus.

False; The mass number of an atom is equal to the number of protons and neutrons in its nucleus. Atomic weight is a weighted average of the isotopes that exists for an element.

How many valence shell electrons does the element carbon have?

Four; Carbon has an atomic number of 6 and has four electrons in its outermost (valence) electron she

What type of bond is formed between the oxygen atom of one water molecule and the hydrogen atom of another water molecule?

Hydrogen bond ; The attraction between the slightly negative oxygen atom of one molecule and the slightly positively charged hydrogen atom within a separate water molecule is the basis of hydrogen bond formation. It is a form of dipole-dipole interaction.

Rank the chemical bonds from relatively weakest to strongest. I. IonicII. CovalentIII. Hydrogen

Hydrogen, ionic, covalent ; Covalent bonds are the strongest because they involve sharing electrons. Ionic bonds are weaker and involve attractions between oppositely charged ions. Hydrogen bonds are the weakest and involve attractions between partial charges.

Which of the following is NOT one of the three major types of chemical reactions?

Hyperbolic; Most chemical reactions exhibit one of three recognizable patterns. They are either synthesis, decomposition, or exchange reactions

How do ions form ionic bonds?

Ions of opposite electrical charges are attracted to each other to balance the charges: Ions of opposite charges are drawn together to balance out their charges. Once they bond, they form an ionic compound that can store and transport the ions, or dissociate (separate), releasing the ions, which can then be used by the body.

What is the difference between kinetic and potential energy?

Kinetic energy is energy in action, while potential energy is stored energy.; Kinetic energy is energy in action. We see evidence of kinetic energy in the constant movement of the tiniest particles of matter, as well as in larger objects. Potential energy is stored energy, which has the capacity to do work but is not presently doing so.

Which of the following is NOT a difference between a compound and a mixture?

Mixtures are homogeneous while compounds are heterogeneous.; Mixtures differ from compounds in several important ways. (1) The chief difference between mixtures and compounds is that no chemical bonding occurs between the components of a mixture. The properties of atoms and molecules are not changed when they become part of a mixture. (2) Depending on the mixture, its components can be separated by physical means—straining, filtering, evaporation, and so on. Compounds, by contrast, can be separated into their constituent atoms only by breaking chemical bonds. (3) Some mixtures are homogenous, while others are heterogeneous. All compounds are homogeneous.

Which of the following is NOT a subatomic particle

Molecule; Atoms are comprised of subatomic particles: protons, electrons, and neutrons. Most atoms do not exist in the free state but instead are chemically combined with other atoms. Such a combination of two or more atoms held together by chemical bonds is called a molecule.

Which subatomic particles contribute to an atom's mass number but not its atomic number?

Neutrons ; Atomic number is the number of protons in an atom, but mass number is calculated by adding both the number of protons and the number of neutrons in an atom.

Atoms of oxygen have a total of 8 electrons. Are these atoms stable, and why or why not?

No, because the atoms have only 6 valence electrons, but need 8 for stability.; To be stable, by the Octet Rule an atom must have 8 electrons in its outermost orbital. With only 6 valence electrons, oxygen atoms are unstable and will seek ways to get or share two more electrons to become stable.

Which of the following distinguishes hydrogen bonds from covalent bonds

Only hydrogen bonds can form between bonds (intermolecular); Because hydrogen bonds are not true bonds, they do not always join atoms together within a single molecule. In water, for example, hydrogen bonds link water molecules together. This is referred to as an intermolecular attraction—it is between different atoms.

What explains the negative charge on the oxygen atom within the water molecule?

Oxygen atoms have a stronger pull on the electrons shared within a covalent bond formed between oxygen and hydrogen.; Oxygen atoms are highly electronegative and pull electrons away from the electropositive hydrogen atom. Also, the nonbonding (lone) electron pairs on the oxygen, which are responsible for bending the molecule, are negative.

Sulfur has an atomic number of 16. Sulfur will form chemical bonds in a similar manner as

Oxygen; Oxygen and sulfur both have six electrons in their valence (outermost) electron shells. Therefore, they will form similar types and numbers of bonds with other atoms

A molecule of water (H2O) is formed by what type of bond?

Polar covalent bonds ; The unequal electron distribution produces a slight negative charge on the oxygen and a slight positive charge on the hydrogens. These slight charges give water many unique characteristics that make it ideal for many physiological processes.

Which particle is indicated by the arrow?

Proton ; Note how the number of the indicated particles in each of the three atoms defines each as a unique element.

Which type(s) of subatomic particles can be located within the nucleus of an atom?

Protons and neutrons; In a typical atom, the protons and neutrons "hang out" together in the center of the atom—the nucleus. Electrons are always found orbiting around the nucleus.

Energy that travels in waves. Part of the electromagnetic spectrum.

Radiant energy

Which of the following is true of polar covalent bonds?

The electrons are shared unequally.; Because the electrons are shared unequally, they spend more time around one atom than the other, causing a slight negative charge where they tend to hang out the most, and a slight positive charge where they spend the least time.

When an ionic bond forms, which part(s) of the atoms are directly involved?

The outermost electrons; In ionic bonding, the atoms' outermost electrons—the valence electrons—are closest to each other and will interact, which leads to bond formation.

Which of the following statements regarding atoms is true?

The reactivity of an atom is based on the number of electrons in its outer valance shell.; Yes, you can predict whether an atom will be chemically inert or reactive based on the number of electrons in its outermost energy level (valence shell).

What do these four elements have in common?

They all have an incomplete valence electron shell.; The valence shell is the outermost electron energy level. Valence shell electrons determine the reactivity of an element

Which of the following is NOT considered a factor in influencing a reaction rate?

Time

Which of these elements would be MOST likely to be radioactive?

Tritium; Tritium is the heaviest isotope and is the most likely of the three to be radioactive.

All salts are ionic compounds, but not all ionic compounds are salts.

True; Salts are ionic compounds that contain a cation other than H+ and an anion other than OH-.

Which of the following is not a result of hydrogen bonds?

Two hydrogen atoms join together to form a molecule of hydrogen gas.; Hydrogen bonds occur when there are polar covalent molecules present, but hydrogen atoms join with each other through nonpolar covalent bonds.

Number of protons in an atom.; atomic number

Usually, the first one or two letters of an element's name.; atomic symbol Combined number of protons and neutrons in an atom.; mass number of an element

Which parts of atoms can interact (react) to form chemical bonds?

Valence electrons; Only the outermost parts of atoms interact (react) with each other, and those are the valence electrons. If the outermost orbital is full, the atom is stable and less likely to react with another atom.

Carbon atoms have four valence electrons. Are they likely to react with other atoms, and why or why not?

Yes, because they can become more stable by doing so; Atoms react with other atoms to gain stability, typically by gaining, losing, or sharing electrons to attain a full outermost orbital. Atoms with full outermost electron orbitals are less likely to react and are referred to as being inert

. Which of the following best describes an isotope?

a structural variation in which different atoms of the same element have different numbers of neutrons; Nearly all known elements have two or more structural variations called isotopes, which have the same number of protons and electrons but differ in the number of neutrons they contain.

what is an ion?

an atom that has either gained or lost electron(s); Ions form when atoms gain or lose electrons to attain a full valence shell, which gives them an electrical charge. Ions can be stored in the body, such as ions of calcium and phosphate that are stored in our bones or can be available individually for many physiological processes. For example, Na+ is required for muscle contraction, nerve impulse conduction, and regulation of blood pressure

what is a cation?

an atom that loses one or more electrons and acquires a net positive charge

What holds the sodium and chloride ions together in a chemical bond?

an electrical attraction between opposite charges-The transfer of an electron results in ions with opposite charges that are electrically attracted to each other.

Which four elements comprise approximately 96% of our body weight?

carbon, oxygen, hydrogen, and nitrogen.; The four elements carbon, oxygen, hydrogen, and nitrogen make up about 96% of our body weight; 20 others are present in the body, some in trace amounts.

When the bonds of ATP are broken, energy is released to do cellular work

chemical energy

A type of bond important in tying different parts of the same molecule together into a three-dimensional structure.

hydrogen bond

Covalent bonds

involve the sharing of one to three pairs of electrons; In single covalent bonds, one pair of electrons is shared; in double covalent bonds two pairs are shared; and triple covalent bonds involve sharing of three pairs of electrons. Double covalent bonds are common between carbon atoms in some organic molecules

A bond in which electrons are completely lost or gained by the atoms involved

ionic bond

What does this figure depict?

ionization, followed by formation of an ionic bond; An ionic bond is formed following the complete transfer of one or more electrons from one atom to another

The three atoms shown represent different

isotopes;These three atoms have the same number of protons and are therefore different variations of the same element. They vary because each contains a different number of neutrons; therefore, they are different isotopes of the element hydrogen (atomic number = 1)

Can be measured only by its effects on matter

mass

Anything that occupies space and has mass

matter

Legs moving the pedals of a bicycle

mechanical energy

Which of the following is chemically inert (unreactive)?

neon (atomic number 10)

Subatomic particle having an AMU (Atomic Mass Unit) of zero

neutron

A bond in which electrons are shared equally

nonpolar covalent bond

Lithium has an atomic number of 3. How many electrons are there in the outermost (valence) shell?

one

A bond in which electrons are shared unequally

polar covalent bond

Formation of hydrogen bonds requires hydrogen atoms and what else?

polar covalent bonds; Hydrogen gets a slight positive charge from the unequal sharing of electrons in polar covalent bonds, and it bonds to another atom with a slightly negative charge, again resulting from unequal electron sharing due to a polar covalent bond