Which two groups of elements in the periodic table are the most reactive?(1 point)
Responses
noble gases and alkali metals
noble gases and alkali metals
halogens and noble gases
halogens and noble gases
alkali metals and halogens
alkali metals and halogens
alkaline earth metals and halogens
alkali metals and halogens
Use the periodic table to answer the question.
An illustration shows the periodic table.
Which statement about nitrogen (N) and phosphorus (P) is correct?
(1 point)
Responses
They have the same number of valence electrons.
They have the same number of valence electrons.
They are both classified as halogens.
They are both classified as halogens.
They have the same number of electron shells.
They have the same number of electron shells.
They are both inert.
They have the same number of valence electrons.
Which property do transition metals have in common?(1 point)
Responses
They usually have low densities.
They usually have low densities.
They are usually very soft.
They are usually very soft.
They are usually very reactive.
They are usually very reactive.
They usually have high melting points.
They usually have high melting points.
Neon and argon are both in Group 18 of the periodic table. Which property do they most likely share?(1 point)
Responses
metallic texture
metallic texture
low or no reactivity
low or no reactivity
strong odor
strong odor
silver color
low or no reactivity
Question
A scientist studies an element that has seven electrons in its outer shell, is fairly toxic, is a gas at room temperature, and is highly reactive. To which group of the periodic table does this element belong?(1 point)
Responses
1 - alkali metals
1 - alkali metals
18 - noble gases
18 - noble gases
2 - alkaline earth metals
2 - alkaline earth metals
17 - halogens
17 - halogens
Which observation most likely indicates that only a chemical change has taken place?(1 point)
Responses
States of matter changes.
States of matter changes.
The change cannot be reversed.
The change cannot be reversed.
The shape changes.
The shape changes.
A reaction occurs.