Checkpoint 4

A student creates a mixture of water and washing soda weighing 10g and a mixture of water and epsom salts weighing 15 grams. He knows that when he mixes the two substances a chemical change will occur. According to the law of conservation of mass, what should the weight of the products be after he mixes them?

• 10g
• 15g
• 5g
• 25g

Tags

NGSS.MS-PS1-5

Which of the following equations demonstrates an actual chemical reaction that forms a new substance?

• 
• 
• 
• 

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which of the following observation indicate that a chemical reaction has taken place. Select TWO correct answers.

• liquid water evaporating as a result of thermal energy from the sun.
• two solutions being mixed together and a solid is formed.
• condensation on the window of a house on a cold day.
• a sugar cube dissolving after it has been dropped in glass of water.
• gas bubbles forming as a cake is baking in the oven.

Tags

NGSS.MS-PS1-2

What DETERMINES the identity of a atom

• netrons
• electrons
• protons
• atomic mass

A student drew atomic models of four elements. Based on the drawing, which element is the least reactive?

• Tin, because it has five energy levels with four electrons in the fifth level.
• Gallium, because it has four levels with three electrons in the fourth level.
• Chlorine, because it has three energy levels with seven electrons in the third level.
• Neon, because it has two energy levels with eight electrons in the second level.

Tags

NGSS.MS-PS1-1

A silver ring reacts with compounds containing sulfur in the air to form silver sulfite, a black substance that makes up the tarnish on the surface of silver object. To remove the tarnish from the ring, students placed it in a pan lined with aluminium foil and added hot water. Baking soda was added to the hot water and stirred. Students made the observation about the process. Which observation of this process provides evidence of chemical reaction?

• Hot water heated the aluminium foil
• The liquid solution changed color
• The pan was lined with aluminum foil
• The hot water cooled

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

The diagram shows a model of an atom, The atom has four different symbols on it, each symbol represents a different role for one of the particles within the atom. In this model, which particle determines the reactivity of this atom?

• Particle W
• Particle X
• Particle Y
• Particle Z

Tags

NGSS.MS-PS1-1

Sulfur ( S) and Argon ( Ar) are two elements found on the periodic table. Which of the following statements describe differences between the two elements. Select TWO correct answers.

• Sulfur ( S ) has 6 valence electrons and argon ( Ar) has 8 valence electrons.
• Sulfur ( S ) is found in period 16 ( 6A ) and ( Ar) is found in period 18 ( 8Ar)
• Sulfur ( S) is chemically stable and argon ( Ar) is chemically stable.
• Sulfur ( S ) is highly reactive and argon ( Ar) is chemically stable.
• Sulfur ( S ) is metalloid and argon ( Ar) is a nonmetal.

Students are studying the physical properties that classify elements as metal, nonmetal and metalloid. Which element would be classified as nonmetals?

• chromium and hassium
• osmium and rutherford
• hydrogen and fluorine
• silicon and tellurium

Which element has chemical properties that are most similar to properties of Selenium, ( Se)

• Arsenic
• Sulfur
• Potassium
• Silicon
• Magnesium