Multiple Choice
A noble gas has ___.
At the center of an atom is a nucleus containing ___.
A stable outer energy level
Protons and neutrons
A __ is a covalent bon involving two pairs of electrons.
Double bond
Predict which electrons will have the higher energy.
Predict which electrons have a stronger attraction to the nucleus.
Step 3
Step 1
Why are electrical wires made with metals?
Metal conducts electricity and chemical bond help electrons travel easily.
A ___ is a pure substance that contains two or more elements.
for a neutral atom of an element, the number of __ is always the same.
Compound
Protons and electrons
When a positively charged ion and a negatively charged ion are attracted to each other, the bond they form is referred as a ____ bond.
The bond that forms between atoms when they share electrons is call a ___ bond
Ionic
Covalent
A molecule of carbon monoxide, CO, has ___ atoms.
Two
What do you observe about the outer energy level of the magnesium before and after it bonded with the chlorine?
What can you conclude about the location of the two electrons after bonding?
Before mg had 2 electrons in the outer shell after they were taken.
One to each cl.
What does the formula H2 stand for?
H2 stands for a molecule of hydrogen in which to nuclei share 1 pair of electrons forming a stable covalent bond.
A sodium atom that is positively charged is written as __.
An ion that has __ or ___ an electrons.
S+
Gained; lost
A molecule is a neutral particle formed when __.
Atoms share electrons
What does part 2 of the diagram represent?
What do the negative and positive signs represent in part 3?
Sodium is losing a electron to cl.
Na became a positive ion and Cl became a negative ion.
Describe the bonds between the hydrogen atoms and the oxygen atom in a water molecule.
Oxygen has a greater attraction for electrons then hydrogen the electrons in this bond is shared unequally so oxygen is slightly negative hydrogen is positive polar bond.
A molecule consisting of two hydrogen atoms joined in a covalent bond would be written as ___.
Removing electrons that are closer to the nucleus takes __ than removing electrons that are farther away from the nucleus.
H2
More energy
A ___ is a combination of chemicals symbols and numbers that tell which elements are present is a molecule and how many atoms of each element are present.
Formula
What has been formed in part 3?
Ionic bond
When atoms of nitrogen and oxygen combine, will they form ionic or covalent bonds?
Covalent bond, elements are nonmetal that cannot easily form ions by losing electrons to bond they chare electrons.
When an atom gains an electron and becomes negatively charged, we refer to it as a ___.
Atoms form __ with other atoms and become more stable.
Negative ion
Chemical bonds
When two or more atoms share electrons unevenly, resulting in a positive charge on one end and a negative charge on the other, they are held together by a __ bond.
Polar
Sodium iodide can be added to table salt, sodium chloride, to produce iodized salt. What do these two compounds have in common?
They both have sodium ion, ionic compounds, and they dissolve in water.