Periodic Table, Elements, Chemical Reactions

It stacks the elements in columns according to the number of valence electrons in an atom of the element. Valence electrons are those in the outermost shell of the atom and the ones that participate in reactions. The number of valence electrons is associated with the element’s reactivity. Elements with the same number of valence electrons behave in a similar way in reactions and so are grouped together in the same column on the periodic table.

What does the amount of valance electrons determine about an element?

• Its row in the table.

• Its atomic number.

• Its atomic mass.

• Its reactivity with other elements.

The maximum number of valence electrons an atom can have is eight, with the exception of helium, which can have only two. In each row, or period, of the periodic table, the last element on the right has the maximum number of valence electrons. Its outermost shell is full, and a new period in which the element on the far left has only one valence electron begins in the next row.

How do you determine how many valance electrons an element has?

• Count how far over it is from the left in its row.

• Count which row it is in.

• They all have eight.

• You can not determine this from the periodic table.

The periodic table is further arranged into three major regions, including the metals, metalloids, and non-metals. Metals are on the left of the table; they are shiny and flexible, conduct heat and electricity, and participate in ionic reactions. Non-metals are on the far right of the table; they are dull and brittle, are poor conductors, and typically participate in ionic reactions.

Which one is NOT a major region of elements in the periodic table?

• Metals

• Mettaloids

• Non metals

• Gases

Carbon and silicon, however, are examples of non-metals that participate in covalent reactions. Metalloids are located in a zig-zagging line between the two other regions. Metalloids are solid semi-conductors. In contrast to metals and non-metals, metalloids participate in covalent reactions.

Where would you look on the table to find the mettaloids?

• In a zigzag line on the right.

• In column 17

• On the bottom

• On the top

Which row shown represents compounds?

• Top row

• Bottom row

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NGSS.MS-PS1-1

What is the smallest building block of matter?

• Compounds

• mixtures

• atoms

• pizza

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Which choice would be a molecule?

• O

• H

• Au

• H₂

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Which of the following is an element?

• H₂O

• C₁₂H₂₂O₁₁

• NaCl

• H₂

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NGSS.MS-PS1-1

Which of the following is a chemical change?

• A rusted can

• A crushed can

• A chopped piece of wood

• Water evaporating

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Liquid becomes a solid at the ________ point.

• melting

• freezing

• boiling

• evaporating

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