Mid-Term TEKS 8.6A-E, 8.7A-B, 8.8A-B

What is the difference between a physical and chemical change? PICK TWO

• Physical change: New substance formed

  Chemical change: No new substance formed

• Physical change: irreversible

  Chemical change: reversible

• Physical change: No new substance formed

  Chemical change: New substance formed

• Physical change: reversible

  Chemical change: irreversible

Tags

NGSS.MS-PS1-5

In a chemical formula, how do I distinguish between a single element and a compound?

• Elements have multiple capital letters, Compounds have one

• Compounds have multiple capital letters,

  Elements have one

• There is no difference

Which elements are present in the following formula?

NaCl

Tags

NGSS.MS-PS1-1

What do the small numbers (subscripts) after an element or compound mean?

• The number of molecules of that substance in the reaction

• The number of atoms of that element in the molecule

• The amount of energy in that substance

• Numbers divisible by the subscript

In the following chemical equation, how many different elements and compounds are represented? 4Fe + 3O₂ → 2FeO₃

• 3 elements and 1 compound

• 2 elements and 2 compounds

• 3 elements and 0 compounds

• 2 elements and 1 compound

Tags

NGSS.MS-PS1-1

Which number represents the atomic number of an element on the periodic table?

Elements in a periodic table are arranged from left to right and top to bottom in order of

• Increasing atomic number

• Increasing specific heat

• Decreasing atomic mass

• Sum of the number of protons and electrons

Instructions for a lab warned students to avoid putting Na in the liquid for the experiment. What element should not be placed in the liquid?

Cohesion sticks water molecules to __________. Adhesion sticks water molecules to ________.

• Other surfaces, each other

• Each other, other water molecules

• Each other, other surfaces

• Other surfaces, other water molecules

What property of water allows a droplet of water to form on top of a penny?