Released Chemistry STAAR

An element has a metallic-grey appearance. It also has the properties of both a metal and a nonmetal. In which section of the periodic table indicated in the illustration would the element most likely be found?

• 1

• 2

• 3

• 4

Answer explanation

"Metalloids are found on the zig-zag line"

A researcher wants to experiment with an element that reacts like phosphorus (P) but has a greater atomic mass. Which element should the researcher select for the experiment?

• Nitrogen (N)

• Sulfur (S)

• Arsenic (As)

• Silicon (Si)

Answer explanation

Elements in the same group (column) have similar properties.

Tags

NGSS.MS-PS1-1

The model of the periodic table in the illustration shows the location of four elements. A student is asked to identify an element that is a pale yellow brittle solid that does not conduct electricity. At which location in this periodic table would the element most likely be found?

• 1

• 2

• 3

• 4

Answer explanation

"Nonmetals on the right"

A student is studying the ways different elements are similar to one another. The illustration contains diagrams of atoms from four different elements. Which two atoms are of elements in the same group in the periodic table?

• Atom 1 and Atom 2

• Atom 1 and Atom 4

• Atom 2 and Atom 3

• Atom 3 and Atom 4

Answer explanation

Elements in the same group (column) have the same number of valence electrons!!!

The periodic table is organized into groups and periods of elements. The characteristics of a certain group of elements are listed in the illustration. Which of these elements is in this group?

• Lithium

• Strontium

• Aluminum

• Silicon

Answer explanation

Elements with two valence electrons are found in Group 2 or 2A.

Which two elements on the periodic table are in the same period?

• Sn and Rb

• F and Cl

• K and Ba

• Se and Te

Answer explanation

All of the elements in the same period have the same number of energy levels!!!!!

Element R and Element Q have the same number of valence electrons. The elements both have similar chemical behavior, but element R has fewer energy levels than Element Q. Which statement best describes the positions of the two elements in the periodic table.

• The two elements are in the same period, with element R the first element in the period and Element Q the last element.

• The two elements are side by side in the same period, with Element Q to the left of Element R

• The two elements are in the same group, with Element R just above Element Q.

• The two elements are in the same group, with Element Q at the top of the group and Element R at the bottom.

Answer explanation

Elements with the same number of valence electrons are found in the same group (column) or family!!!!

Tags

NGSS.MS-PS1-1

The students had to use the information on the flash card to determine possible positions of the two elements on a blank periodic table. Which periodic table has the elements placed in locations that match the information on the flash card.

• 
• 
• 
• 

Answer explanation

Metals on the right!!!!!

Students were asked to identify the location of elements in the periodic table based on clues printed on game cards. Based on the data, which periodic table shows the correct location of the four elements?

• 
• 
• 
• 

Answer explanation

The number of valence electrons identifies the group while the number of energy levels identifies the period.

Tags

NGSS.MS-PS1-1

Which pair of properties describes the elements in Group 18?

• They are chemically stable and liquid at room temperature.

• They have eight valence electrons and are flammable.

• They are magnetic and boil at low temperatures.

• They are gaseous at room temperature and chemically stable.

Answer explanation

The elements of Group 18 are nonreactive (chemically stable) gases.