Physical science

Isra is analyzing the properties of several samples of elements to find out which sample is a metalloid. Which set of properties most likely belongs only to a metalloid?

• forms basic compounds and is a solid

• has a high luster and is very brittle

• is a gas and has low electrical conductivity

• is brittle and forms acidic compounds

Which statement describes the location of metalloids on the periodic table?

• The metalloids are located below metals and above nonmetals within a group.

• The metalloids are located below nonmetals and above metals within a group.

• The metalloids are located to the right of nonmetals and to the right of metals within a period.

• The metalloids are located to the left of nonmetals and to the left of metals within a period.

Which important change in electronic devices, such as televisions and computers, is a result of the use of metalloids as semiconductors?

• Electronic devices have become smaller.

• Electronic devices are now more brittle.

• Electronic devices now use more energy.

• Electronic devices have become more expensive.

Atoms of arsenic (As) are often added to silicon (Si) in a process called doping to change the conductivity of the silicon. How does the addition of arsenic change the conductivity of silicon?

• An atom of arsenic has one fewer valence electron and more electron shells than an atom of silicon, so the conductivity decreases because the arsenic atom gains an electron.

• An atom of arsenic has one more valence electron and more electron shells than an atom of silicon, so the conductivity decreases because the arsenic atom loses the electron.

• An atom of arsenic has one fewer valence electron and fewer electron shells than an atom of silicon, so the conductivity increases because the arsenic atom gains an electron.

• An atom of arsenic has one more valence electron and more electron shells than an atom of silicon, so the conductivity increases because the arsenic atom loses the electron.

Which is the property of nonmetals to evaporate easily?

• Brittle

• dense

• liquid

• volatile

What best describes the states of nonmetals when they are at room temperature?

• Most nonmetals are gaseous, but some are liquid or solid.

• All nonmetals are gaseous unless they bond with a metal.

• Most nonmetals are solids, but some are gaseous or liquid.

• All nonmetals are solid unless they bond with a metal.

These models show the electron structures of two different nonmetal elements. Which element is likely more reactive, and why?

• Element 1 is more reactive because it has fewer electron shells and is toward the top of its group on the periodic table.

• Element 1 is more reactive because it has more electrons in its valence shell and is farther to the right on the periodic table.

• Element 2 is more reactive because it does not have a valence shell close to the nucleus, so it will attract electrons.

• Element 2 is more reactive because it does not have a full valence shell, so it will attract electrons.

Sonya is studying a nonmetal element. She learns that the element is like other elements in its group because it can bond to form a salt or an acid. She also learns that the element is the most reactive element in its group. Which element is Sonya most likely studying?

• sulfur (S)

• neon (Ne)

• fluorine (F)

• iodine (I)

Which element is most likely to carry electric current easily?

• tin (Sn)

• sulfur (S)

• antimony (Sb)

• selenium (Se)

Where are alkaline earth metals found on the periodic table?

• Group 1

• Group 2

• Groups 3–12

• Group 17