Q: A sample contains $$0.50$$ moles of aluminum. How many atoms of aluminum are present? ($$N_A = 6.022 \times 10$$^{23}$$ mol$$^{-1}$$)

$$3.01 \times 10$$^{23}$$ atoms

Question 1

Which of the following statements best describes the arrangement of the periodic table?

Accepted Answer

Metals are found on the left and center, nonmetals on the right, and metalloids form a staircase between them.

Question 2

Which element is a member of the alkali metals family?

Accepted Answer

Na

Question 3

Which property is most characteristic of metals?

Accepted Answer

Malleable and good conductors of heat

Question 4

Which of the following is the correct symbol for the isotope of carbon with 6 protons, 7 neutrons, and a neutral charge?

Accepted Answer

$$^{13}_{6}\mathrm{C}$$

Question 5

How many protons, neutrons, and electrons are in $$^{35}_{17}\mathrm{Cl}^{-}$$?

Accepted Answer

17 protons, 18 neutrons, 18 electrons

Question 6

Which pair of species are isotopes of each other?

Accepted Answer

$$^{12}_{6}\mathrm{C}$$ and $$^{14}_{6}\mathrm{C}$$

Question 7

Given the following isotopic abundances for magnesium: $$^{24}\mathrm{Mg} (78.99$$%, mass = 23.985 amu), $$^{25}\mathrm{Mg} (10.00$$%, mass = 24.986 amu), $$^{26}\mathrm{Mg} (11.01$$%, mass = 25.983 amu), calculate the average atomic mass of magnesium.

Accepted Answer

$$24.31$$ amu

Question 8

Which element is a noble gas?

Accepted Answer

Ar

Question 9

A sample contains $$0.50$$ moles of aluminum. How many atoms of aluminum are present? ($$N_A = 6.022 	imes 10$$^{23}$$ mol$$^{-1}$$)

Accepted Answer

$$3.01 	imes 10$$^{23}$$ atoms

Question 10

Which of the following best describes the charge and location of a neutron in an atom?

Accepted Answer

No charge, located in the nucleus

Question 11

Which of the following nuclear reactions is balanced?

Accepted Answer

$$^{14}_{6}\mathrm{C} \$$rightarrow ^{14}$$_{7}\mathrm{N} $$+ ^{0}$$_{-1}\mathrm{e}$$

Question 12

Which element is a metalloid?

Accepted Answer

Si

Question 13

Which of the following elements is most likely to form a $$2+$$ ion?

Accepted Answer

Mg

Question 14

If you have $$12.0 g of $$carbon ($$M = 12.0 g/$$mol), how many moles do you have?

Accepted Answer

$$1.00$$ mol

Question 15

Which of the following is a correct statement about the similarities within a group (family) on the periodic table?

Accepted Answer

Elements in a group have similar chemical behavior and form similarly charged ions.

Question 16

Which of the following is the correct symbol for an ion with 20 protons, 20 neutrons, and 18 electrons?

Accepted Answer

$$^{40}_{20}\mathrm{Ca}^{2+}$$

Question 17

Which of the following is a real-world application of the concept of isotopes?

Accepted Answer

Carbon dating uses the ratio of $$^{14}\mathrm{C} to$$ $$^{12}\mathrm{C} to $$estimate the age of ancient artifacts.

Question 18

Which of the following elements is a transition metal?

Accepted Answer

Fe

Question 19

A student has $$3.01 	imes 10$$^{23}$$ atoms of silver. What is the mass of this sample? (Molar mass of Ag = 107.9$ g/mol, N_A = 6.022$$ 	imes $$10^{23}$$ mol$$^{-1})$$

Accepted Answer

$$53.95 g$$

CHEM 1910 Foundations of Chemistry: Atomic Perspective and Periodic Table Study Guide

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