Science TEKS 8.5A

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

A student obtains two strips of magnesium, Mg, ribbon that are each 3 cm long. One strip of magnesium is placed in a test tube containing 5 mL of water, and the other strip is placed in a test tube containing 5 mL of hydrochloric acid, HCl. Both liquids are at room temperature. The student’s observations are recorded in the table. Which statement is not supported by the student’s observations?

• A chemical reaction takes place between magnesium and hydrochloric acid.

• A gas is released in Test Tube 2.

• The substances in both test tubes are reactive only at high temperatures.

• Energy is released in the reaction involving hydrochloric acid.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-4

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.HS-LS1-6

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 below. Which student’s responses are correct?

• Student 1

• Student 2

• Student 3

• Student 4

Tags

NGSS.MS-PS1-1

chemical reaction in which calcium carbonate, CaCO₃, is decomposed results in the production of two simpler compounds. What mass of calcium carbonate, to the nearest hundredth of a gram, is decomposed in this reaction?

• 21.97g

• 28.00g

• 49.97g

• 6.03g

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Nitrogen dioxide is a gas that can be generated by emissions from vehicles and factories. It can also be generated by natural sources, such as forest fires, lightning, and microbial activity in soil. The equation for producing nitrogen dioxide is shown below. Which of these provides evidence that a chemical reaction occurs?

• A gas is present.

• The total number of atoms remains unchanged.

• The state of matter remains the same.

• A brown gas is produced.

Tags

NGSS.MS-PS1-2

A balance and a graduated cylinder are used to determine the density of a mineral sample. The sample has a mass of 14.7g and a volume of 2.2cm³ .What is the density of the

mineral sample?

• 0.15 g/cm³

• 32 g/cm³

• 13 g/cm³

• 6.7 g/cm³

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)

A model of an atom is shown. An atom of which element is represented by this model?

• Boron (B)

• Carbon (C)

• Neon (Ne)

• Sodium (Na)

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.

Tags

NGSS.MS-PS2-3