STAAR Science

Which of these substances are elements?

• S, Fe, O₂, Sr, and Al 
• S, O₂, and LiF
• N₂O₄, O₂, and LiF 
• N₂O₄, Fe, Sr, and Al 

A teacher rubbed a match against a piece of sandpaper. The match started to burn.
Which statement best describes the energy changes that occurred?

• The chemical energy stored in the match changed to thermal energy and light energy.
• The thermal energy stored in the match changed to light energy and chemical energy.
• The light energy and thermal energy stored in the match changed to mechanical energy.
• The light energy and thermal energy stored in the match changed to chemical energy. 

Tags

NGSS.MS-PS3-4

NGSS.MS-PS3-5

Four students were given a list of compounds and asked to identify which ones are organic. 
Which student correctly identified the organic compounds in the list?

• Student K
• Student L
• Student M
• Student N

Tags

NGSS.MS-PS1-3

How many protons, neutrons, and electrons are present in an atom of hafnium, Hf, with a mass number of 178?

• 72 protons, 178 neutrons, 106 electrons
• 72 protons, 106 neutrons, 72 electrons
• 178 protons, 250 neutrons, 72 electrons
• 106 protons, 72 neutrons, 106 electrons

Tags

NGSS.MS-PS1-1

What is the difference between the number of electrons in an atom of selenium, Se, and the number of electrons in an atom of aluminum, Al?

• 13
• 21
• 34
• 47

Four students were asked to name the parts of an atom that determine the atom’s identity and chemical properties. The students’ responses are shown in the table. 
Which student’s responses are correct? 

• Student 1
• Student 2
• Student 3
• Student 4

Tags

NGSS.MS-PS1-1

Tin, Sn, is a soft white metal. It has a low melting point compared with other metals. Tin is widely used as a coating for cans of food.
Which statement accurately describes atoms of tin?

• Tin atoms have 50 protons.
• Tin atoms have five valence electrons.
• Tin atoms have 119 neutrons.
• Tin atoms have 68 electrons.

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?

• Both L & M are in group 2.
• M is in group 14 & L is in group 16
• M is in group 1 & L is in group 2.
• L in Group 1 & M is in group 13.

Tags

NGSS.MS-PS1-1

Element R and Element Q have the same number of valence electrons. These 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.

Tags

NGSS.MS-PS1-1

Strontium phosphate, Sr₃(PO₄)₂, is a crystalline substance used in medicine and industry.
How many phosphorus atoms are represented in the formula for Sr₃(PO₄)₂?

• 2
• 3
• 4
• 8

Tags

NGSS.MS-PS1-1