Assignment 1

All samples of a given compound, regardless of their source or how they were prepared, have the same proportions of their constituent elements. Which law does this refer to? Law of Modern Atomic Theory Law of Definite Proportions Law of Multiple Proportions Law of the Conservation of Mass

Law of Definite Proportions

What species is represented by the following information? p+ = 12 n° = 14 e- = 10 Mg2+ Si4+ Mg Si

Mg2+

Of the choices below, which one is not an ionic compound? RbBr NaCl CuO PCl5

PCl5

Which pair of elements would you expect to exhibit the greatest similarity in their physical and chemical properties? S, Se Ca, S Cs, Ba Ga, Ge

S, Se

Which of the following statements is FALSE? Noble gases do not usually form ions. The alkali metals are fairly unreactive. Sulfur is a main group element. Halogens are very reactive elements.

The alkali metals are fairly unreactive.

Which of the following elements is NOT a metal? Ba Xe Pb Mg

Xe

How many moles of Kr are contained in 398 mg of Kr? 0.00299 moles Kr 0.00475 moles Kr 0.000211 moles Kr 33.4 moles Kr

0.00475 moles Kr

Calculate the atomic mass of silver if silver has 2 naturally occurring isotopes with the following masses and natural abundances: Ag-107 106.90509 amu 51.84% Ag-109 108.90476 amu 48.46% 108.32 amu 108.00 amu 107.90 amu 108.19 amu

108.19 amu

The correct result (indicating the proper number of significant figures) of the addition, 12 + 1.2 + 0.12 + 0.012 is 13.3 13 13.33 13.332

13

A temperature of __________ K is the same as 63°F. 29 273 290 17

290

The correct answer (reported to the proper number of significant figures), 16.5 × 23.25 = 384 383.6 383.63 383.625

384

Calculate the mass (in kg) of 4.87 x 1025 atoms of Zn. 5.29 kg 8.09 kg 1.24 kg 1.89 kg

5.29 kg

Which of the following statements is FALSE according to Dalton's Atomic Theory? An atom of nitrogen can be broken down into smaller particles that will still have the unique properties of nitrogen. Atoms combine in simple whole number ratios to form compounds. Atoms of sodium do not change into another element during chemical reaction with chlorine. All atoms of chlorine have identical properties that distinguish them from other elements.

An atom of nitrogen can be broken down into smaller particles that will still have the unique properties of nitrogen.

The ions Ca2+ and PO43- form a salt with the formula __________. Ca(PO4)2 Ca2(PO4)3 CaPO4 Ca3(PO4)2

Ca3(PO4)2

Accuracy refers to __________. how close a measured number is to other measured numbers how close a measured number is to zero how close a measured number is to the calculated value how close a measured number is to the true value

how close a measured number is to the true value

Determine the number of protons, neutrons and electrons in the following: p+ = 18 n° = 22 e- = 18 p+ = 18 n° = 18 e- = 22 p+ = 22 n° = 18 e- = 18 p+ = 18 n° = 22 e- = 40

p+ = 18 n° = 22 e- = 18

The correct name for K2S is __________. potassium disulfide potassium bisulfide potassium sulfate potassium sulfide

potassium sulfide

Which of the following does NOT describe a metal? good conductor of heat good conductor of electricity forms ionic compounds with nonmetals tends to gain electrons

tends to gain electrons

The atomic number indicates __________. the total number of neutrons and protons in a nucleus the number of neutrons in a nucleus the number of atoms in 1 g of an element the number of protons or electrons in a neutral atom

the number of protons or electrons in a neutral atom

The mass number is equal to the sum of the number of the electrons and protons. the sum of the number of protons, neutrons, and electrons. the sum of the number of protons and neutrons. the sum of the number of the neutrons and electrons.

the sum of the number of protons and neutrons.