Core Ideas of Chemistry

The bonds within a water molecule are:

• Polar covalent

• Hydrogen

• Ionic

• Non-polar covalent

Water is often called the “universal solvent” because many substances can be dissolved in water. What property of water allows it to be such a universal solvent?

• Purity

• Polarity and cohesion

• High heat capacity

• Expansion upon freezing

Any compound that removes H+ ions to an aqueous solution and measures more than 7 on the pH scale:

• Base

• Solvent

• Acid

• Solute

Why does ice float?

• As water freezes, it expands and its density decreases.

• As water freezes, air becomes trapped between the hydrogen bonds of water molecules. 

• As water freezes, it takes up more hydrogen from the atmosphere, causing it to have greater buoyancy (floating ability). 

• As water freezes, it takes up more oxygen from the atmosphere, causing it to have greater buoyancy.

Substance in a solution that dissolves the other substance and is present in the greater amount:

• Solute

• Acid

• Solution

• Solvent

Any compound that donates H+ ions to an aqueous solution and measures less than 7 on the pH scale:

• Acid

• Base

• Solvent

• Solute

What are the 3 particles that make-up the atom?

• protons, neutrons, and isotopes

• neutrons, isotopes, and electrons

• positives, negatives, and electrons

• protons, neutrons, and electrons

Tags

NGSS.MS-PS1-1

You know you a chemical reaction has occurred if 

• there is a precipitate.

• there is a color change.

• there is a temperature change.

• All of these answers are evidence.

Tags

NGSS.MS-PS1-2

Copper(II) carbonate breaks down to form carbon dioxide and copper(II) oxide when heated. This is an example of a:

• decomposition reaction.

• synthesis reaction.

• precipitation reaction.

• acid-carbonate reaction.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS1-5

In the equation,          2Mg + O₂ ---> 2MgO, which are the reactants?

• Mg and O

• MgO

• Mg and MgO

• O and MgO

Tags

NGSS.MS-PS1-2