Launchpad week 1

The ability of atoms to attract electrons is referred to as:

electronegativity

The unique properties of water are due to the _____ of water molecules and the ability of water to form _____ with other water molecules and with other polar molecules.

polarity; hydrogen bonds

Which of the following CORRECTLY pairs the particles of an atom with their physical properties?

proton - positive, electron - negative, neutron - neutral

Sometimes, atoms gain or lose particles. The loss of which of the following would result in a change of overall electrical charge?

protons or electrons

Water is able to dissolve many compounds as a result of which of the following?

the fact that water molecules are polar

For an atom that is NOT an ion, which of the following must be TRUE?

the number of electrons equals the number of protons

A woman's doctor tells her to gargle with salt water. She stirs a tablespoon of salt into a cup of warm water and watches it dissolve. Why does the salt dissolve in water?

the positive hydrogen atoms in water molecules are attracted to chlorine ions, and the negative oxygen atoms in water molecules are attracted to sodium ions

A molecule of common table salt, or NaCl, is the result of _____ bond forming between a sodium (Na) atom and a chlorine (Cl) atom.

an ionic

The structural formula for hydrogen gas (H2) is represented as H?H. Here, the dash (?) represents a(n):

chemical bond

A polar bond is due to:

uneven sharing of electrons in a covalent bond

Of the following types of bonds or interactions between atoms, which is the WEAKEST? van der Waals forces, ionic bond, hydrogen bond, covalent bond

van der Waals forces

Which of the following statements is TRUE regarding a polar molecule?

A polar molecule is hydrophilic and it will dissolve in water.

Molecule X could form a hydrogen bond with water:

True

Molecule X could form an ionic bond with Na+:

True

Refer to the periodic table, and decide which of the following molecules is held together by polar covalent bonds. CH4 KCl NH3

NH3

Molecule X could form a hydrogen bond with another Molecule X:

False

Molecule X could form an ionic bond with Cl-:

False

Water is neither hydrophilic nor hydrophobic, because these terms only define the interaction of other molecules with water molecules.

False

Sometimes, atoms gain or lose particles. The loss of which of the following results in a change of atomic mass?

a neutron and a proton

How many hydrogen atoms are present in a hydrocarbon chain of five carbon atoms with two double bonds and two single bonds?

8

Three carbon atoms are linked by single covalent bonds such that they form the shape of a V. All of the unshared electrons form covalent bonds with hydrogen. How many hydrogen atoms does this molecule contain?

8

Refer to the periodic table, and decide which of the following molecules is held together by nonpolar covalent bonds. CH4 KCl NH3

CH4

Refer to the periodic table, and decide which of the following molecules is held together by ionic bonds. CO2 NH3 KCl

KCl