Atoms and Bonding

Match the Following

• A substance that cannot be broken down into simpler substances by chemical means.

• Element

• The dense center of an atom containing protons and neutrons.

• Nucleus

• The smallest unit of an element that keeps the element’s chemical properties.

• Neutron

• Particles with a neutral charge found in the nucleus of an atom.

• Atom

• Positively charged particles found in the nucleus of an atom.

• Proton

Match the following

• Vertical columns of elements that have the same amount of valence electrons.

• Family/Group

• Elements that are malleable, ductile, and good conductors; typically shiny.

• 15) Metal

• Horizontal rows of elements that have the same number of electron shells. 

• Period

• The average number of protons and neutrons in one atom of an element.

• Periodic Table

• All known elements arranged in order by atomic number.

• Atomic Mass/Mass Number

How many valence electrons does the pictured atom have?

• 20

• 3

• 2

• 4

Balance this equation

_Al +_HCl --> _H₂ +_AlCl₃

• 2,6,3,2

• it's already balanced

• 4,12,3,4

• 2,1,4,5

How many HCl molecules do you need to balance this equation? 
Mg +  __HCl --->  MgCl₂ + H₂

• 1
• 2
• 3
• 4

Which number should go in the blank?
Al(NO₃)₃ + _  NaOH -> Al(OH)₃ + 3 NaNO₃

• 1
• 2
• 3
• 0

What are the coefficients that would properly balance this equation?

__AgNO₃ + __H₂S --> __Ag₂S+ __HNO₃

• 2,1 --> 1,2

• 1,2 --> 1,1

• 1,2 --> 1,2

• 1,2 --> 2,1

Balance this equation:
MgCl₂ --> Mg₄+ Cl₂

• It's already balanced.
• 4MgCl₂ --> Mg₄+ 4Cl₂
• 4MgCl₂ --> Mg₄+ 5Cl₂

The number of atoms you begin with in a chemical reaction ...

• must be the same as the number of  atoms you end with
• must be an even number
• can be different to the number you finish with
• changes depending on how much energy is formed

Which of the following is a common sign that a chemical change has occurred?

• A chemical has turned a different color, bubbled, and/or changed temperature.

• A chemical has changed to a different state of matter, such as a liquid to a solid.

• A chemical has changed size.

• A chemical has become a different shape.