Science STAAR Constructed Responses

A scientist spilled a few drops of dilute hydrochloric acid (HCl) on a lab table. For safety purposes, the scientist sprinkled some baking soda (NaHCO3) onto the spill. Which observation would provide the best evidence that a chemical reaction occurred?

• The baking soda and hydrochloric acid combined, and bubbles formed.

• The baking soda absorbed the hydrochloric acid.

• Some of the baking soda dissolved in the hydrochloric acid.

• The hydrochloric acid evaporated, leaving only the baking soda.

Tags

NGSS.MS-PS1-2

Some students take care of a vegetable garden. When it is time to plant in the spring, the students leave part of the garden empty in order to observe ecological succession. Which of these will most likely occur first?

• Development of the topsoil

• Growth of weeds and grasses

• Growth of trees and shrubs

• Development of a stream

Where are the genes for the physical traits of an organism located?

• on a strand of RNA

• on a chromosome

• inside a hormone

• inside a carbohydrate

An atom of which element is represented by the model below?

• Carbon

• Boron

• Lithium

• Oxygen

Tags

NGSS.MS-PS1-1

Which of the following best describes an electron?

• It has no charge and about the same mass as a proton.

• It has a negative charge and much less mass than a proton.

• It has a positive charge and much more mass than a neutron.

• It has a negative charge and about the same mass as a neutron.

To express the distance between the Milky Way galaxy and other galaxies, the most appropriate unit of measurement is the –

• meter.

• kilometer.

• light-year.

• astronomical unit.

Which of these describes a divergent boundary?

• Two continental plates moving away from each other, forming a rift valley

• Two oceanic plates rubbing against each other, forming a mid-ocean ridge

• Two continental plates colliding, forming a mountain range

• Two oceanic plates colliding, forming a volcanic arc

Different species of carnivorous animals that share the same habitat in an ecosystem may –

• become decomposers

• compete for biotic food

• produce their own food

• mate with each other

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-2

What are the main elements in many organic compounds?

• Helium, carbon, sodium

• Sodium, hydrogen, nitrogen

• Carbon, hydrogen, oxygen

• Radon, oxygen, helium

Tags

NGSS.MS-LS1-6

Some students measure the acceleration of a wheeled cart being acted on by varying forces. The students record their data in the table shown below. According to the data table, how much force is acting on the cart when the students measure an acceleration of 2.6 m/s?

• 13 N

• 7 N

• 8 N

• 12 N

Tags

NGSS.MS-PS2-2