3. explain are all compounds molecules? why or why not? 4. compare ionic bonds and covalent bonds. 5…
3. explain are all compounds molecules? why or why not? 4. compare ionic bonds and covalent bonds. 5. explain how the number of electrons in an energy level affects bond formation. 6. beryllium has four protons in its nucleus. how many neutrons are in beryllium - 9? explain how you calculated your answer.
Answer
3.
Brief Explanations:
Not all compounds are molecules. Compounds are substances made of two or more elements. Molecules are formed by covalent - bonding. Ionic compounds, held together by ionic bonds, are not molecules. For example, sodium chloride (NaCl) is a compound but not a molecule as it exists as a crystal - lattice of ions.
Answer:
No, because some compounds like ionic compounds are not held together by covalent bonds to form molecules.
4.
Brief Explanations:
Ionic bonds form when one atom donates electrons to another, creating ions that attract each other. Covalent bonds form when atoms share electrons. Ionic compounds often form crystals and have high melting points, while covalent compounds can be gases, liquids or solids with lower melting and boiling points in general.
Answer:
Ionic bonds involve electron - transfer and attraction between ions; covalent bonds involve electron - sharing. Ionic compounds usually have higher melting points and form crystals, while covalent compounds have more variable physical states and lower melting/boiling points in general.
5.
Brief Explanations:
Atoms aim for a stable electron configuration, often with a full outer energy level. If an energy level is not full, atoms can gain, lose or share electrons to achieve stability, forming bonds. For example, atoms with 1 - 3 valence electrons may lose them, while those with 5 - 7 may gain electrons to fill their outer shell.
Answer:
Atoms try to fill their outer energy levels for stability. Depending on the number of electrons in an energy level, atoms will gain, lose or share electrons to form bonds.
6.
Explanation:
Step1: Recall the atomic - mass formula
The atomic mass (A) is the sum of protons (p) and neutrons (n), i.e., $A=p + n$.
Step2: Identify given values
Beryllium - 9 has an atomic mass $A = 9$ and the number of protons $p=4$.
Step3: Solve for neutrons
We can rewrite the formula as $n=A - p$. Substituting the values, we get $n = 9-4$.
Answer:
- We used the formula $n=A - p$, where $A = 9$ (atomic mass of beryllium - 9) and $p = 4$ (number of protons in beryllium), so $n=9 - 4=5$.