The smallest unit of matter that retains the chemical identity of the the elements

• Element

• Atom

• Compound

• Molecule

A pure substance made of one kind of atom that cannot be broken down chemically into simpler substances.

• Element

• Atom

• Compound

• Molecule

A pure substance made by chemically combining two or more elements; represented by a chemical formula.

• Element

• Atom

• Compound

• Molecule

Tags

NGSS.MS-PS1-1

The simplest unit (particle) of a compound that can exist; formed when two or more atoms combine chemically.

• Element

• Atom

• Compound

• Molecule

Tags

NGSS.MS-PS1-1

Compare and contrast the following tiles, and determine whether each is a chemical symbol or a chemical formula. Use the table to sort the tiles into their respective categories.

Groups:

(a) Chemical Symbols

,

(b) Chemical Formulas

• CO

• Cl

• C

• O

• Na

• NaH

• H

• NaCl

• HCl

Compare the compounds to determine the elemental composition in each by placing each correct answer next to the corresponding chemical formula.

H₂O = ​ (a)   ​ ​ ​ (b)  

CO₂ = ​ (c)   ​ (d)  

• 2 hydrogen atoms
• 1 oxygen atom
• 1 carbon atom
• 2 oxygen atoms

Tags

NGSS.MS-PS1-1

Determine the elemental composition of the compound below.

C₁₂H₂₂O₁₁ = ​ (a)   ​ (b)   ​ (c)  

• 12 carbon atoms
• 22 carbon atoms
• 22 hydrogen atoms
• 11 hydrogen atoms
• 11 oxygen atoms
• 12 oxygen atoms

Tags

NGSS.MS-PS1-1

Oxygen forms molecules made of two atoms, O₂. Carbon and oxygen form molecules made of one carbon atom and two oxygen atoms, CO₂. Which of the statements below is true?

• Both O₂ and CO₂ are compounds.

• Both O₂ and CO₂ are molecules.

• O₂ is a compound while CO₂ is a molecule.

• O₂ is a molecule while CO₂ is a compound.

Tags

NGSS.MS-PS1-1

Compare and contrast the chemical symbols and formulas in the table. Complete each row of the table by determining whether it is a chemical symbol or a chemical formula?

Groups:

(a) Chemical Symbol

,

(b) Chemical Formula

• HCl

• Li

• NaF

• Ti

• LiI

• CO

The following two representations of oxygen that are similar and different. Which two statements is true about what the letter means and what the subscript means?

O and O₂

• The letter O represents the element oxygen.

• The letter O represents its placement on the periodic table.

• The number in O₂ represents the number of oxygen atoms that are bound to form a molecule.

• The number in O₂ represents the number of oxygen atoms that are bound to form a element.

Tags

NGSS.MS-PS1-1