Chemistry Star Review

Some students are using samples of different substances for a lab investigation. They plan to observe the physical properties of each substance and record their observations in a table like the one below. Which of the substances observed are elements?

• S, Fe, O, Sr, and Al

• S, O, and LiF

• NO, O,and LiF

• NO,Fe,Sr,and Al

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

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-PS1-5

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-PS1-1

How many valence electrons does Potassium Have?

• 1 Valence electron

• 2 Valence electron

• 3 Valence electron

• 4 Valence electron

• 5 Valence electron

How many valence electrons does Silicon Have?

• 1 Valence electron

• 2 Valence electron

• 3 Valence electron

• 4 Valence electron

• 5 Valence electron

Tags

NGSS.MS-PS1-1

Which item on this element square is the chemical symbol?

• Copper

• 29

• Cu

• 63.546

This shows a table salt molecule. What is it?

• compound

• element

• mixture

Tags

NGSS.MS-PS1-1

An element is

• Made up of different types of atoms

• Made up of the same type of atoms

• none of the above

• all of the above

Tags

NGSS.MS-PS1-1

Which of these samples shown best represents an element?

• A

• B

• C

• D

Tags

NGSS.MS-PS1-1