Question

basic chemistry assignment
objective: to reinforce fundamental chemistry concepts through independent work and practice.
assignment overview
students will complete a series of exercises based on key chemistry topics. the assignment will be divided into sections focused on different concepts. students are expected to work independently and submit their answers by the end of the week.
part 1: atomic structure (due: insert due date)

1. fill in the blanks:

complete the following sentences related to atomic structure:

• the three main subatomic particles are __, , and __.
• the nucleus of an atom contains __ and __.
• the number of protons in an atom determines its ____.

1. draw an atom:

choose an element from the periodic table (e.g., carbon, oxygen, sodium) and draw its atomic structure. label the protons, neutrons, electrons, and nucleus.
part 2: the periodic table (due: insert due date)

1. short answer questions:

• what information can you find in each box of the periodic table?
• describe the difference between a group and a period in the periodic table.
• name three elements that are gases at room temperature.

1. element research:

select one element from the periodic table. write a brief paragraph (4 - 5 sentences) about its properties, common uses, and any interesting facts.
part 3: chemical reactions (due: insert due date)

1. identify the types of reactions:

given the following equations, identify the type of chemical reaction (synthesis, decomposition, single - replacement, double - replacement, or combustion):

• a + b → ab
• ab → a + b
• a + bc → ac + b
• ab + cd → ad + cb
• c + o₂ → co₂

1. balance the equations:

balance the following chemical equations:

• h₂ + o₂ → h₂o
• na + cl₂ → nacl
• c₃h₈ + o₂ → co₂ + h₂o

Explanation:

Part 1: Atomic Structure

1. Fill in the Blanks

- The three main subatomic particles are protons, neutrons, and electrons. Protons have a positive charge, neutrons are neutral, and electrons have a negative charge.
- The nucleus of an atom contains protons and neutrons. The nucleus is the dense, central part of the atom.
- The number of protons in an atom determines its atomic number. Each element has a unique atomic number.

2. Draw an Atom

For example, if we choose carbon (C). Carbon has an atomic number of 6, so it has 6 protons. In a neutral - carbon atom, it also has 6 electrons. The most common isotope of carbon has 6 neutrons. Draw a small circle to represent the nucleus. Place 6 protons and 6 neutrons inside the nucleus. Then draw two electron - shells around the nucleus. Place 2 electrons in the first shell and 4 electrons in the second shell. Label the protons, neutrons, electrons, and nucleus accordingly.

Part 2: The Periodic Table

1. Short Answer Questions

- In each box of the periodic table, you can find the element's symbol, atomic number, atomic mass, and sometimes its name.
- A group in the periodic table is a vertical column. Elements in the same group have similar chemical properties because they have the same number of valence electrons. A period is a horizontal row. As you move across a period, the number of protons and electrons increases, and the elements change from metals to non - metals.
- Three elements that are gases at room temperature are hydrogen (H), oxygen (O), and nitrogen (N).

2. Element Research

Let's choose oxygen (O). Oxygen has an atomic number of 8 and an atomic mass of approximately 16.00. It is a non - metal and is essential for respiration in most living organisms. It is also used in combustion processes, such as in engines and furnaces. An interesting fact is that oxygen makes up about 21% of the Earth's atmosphere.

Part 3: Chemical Reactions

1. Identify the Types of Reactions

- \(A + B ightarrow AB\) is a synthesis reaction, where two or more substances combine to form a single product.
- \(AB ightarrow A + B\) is a decomposition reaction, where a single compound breaks down into two or more simpler substances.
- \(A+BC ightarrow AC + B\) is a single - replacement reaction, where one element replaces another element in a compound.
- \(AB + CD ightarrow AD+CB\) is a double - replacement reaction, where the positive and negative ions of two ionic compounds exchange places.
- \(C + O_2 ightarrow CO_2\) is a combustion reaction, where a substance reacts with oxygen to produce carbon dioxide (and often water).

2. Balance the Equations

- For \(H_2+O_2 ightarrow H_2O\), the balanced equation is \(2H_2 + O_2 ightarrow 2H_2O\).
- Step1: Balance hydrogen. There are 2 hydrogen atoms on the left - hand side and 2 on the right - hand side in the unbalanced equation. But there are 2 oxygen atoms on the left and 1 on the right. Multiply \(H_2O\) by 2 to get 2 oxygen atoms on the right. Then multiply \(H_2\) by 2 to balance hydrogen.
- For \(Na + Cl_2 ightarrow NaCl\), the balanced equation is \(2Na+Cl_2 ightarrow 2NaCl\).
- Step1: Balance chlorine. There are 2 chlorine atoms on the left and 1 on the right. Multiply \(NaCl\) by 2. Then multiply \(Na\) by 2 to balance sodium.
- For \(C_3H_8+O_2 ightarrow CO_2 + H_2O\), the balanced equation is \(C_3H_8+5O_2 ightarrow 3CO_2 + 4H_2O\).
- Step1: Balance carbon. There are 3 carbon atoms in \(C_3H_8\), so put a 3 in front of \(CO_2\).
- Step2: Balance hydrogen. There are 8 hydrogen atoms in \(C_3H_8\), so put a 4 in front of \(H_2O\).
- Step3: Balance oxygen. There are \(3\times2 + 4\times1=10\) oxygen atoms on the right - hand side. So put a 5 in front of \(O_2\) on the left - hand side.

Answer:

• Part 1:
• 1. protons, neutrons, electrons; protons, neutrons; atomic number
• 2. (Example for carbon) Nucleus with 6 protons and 6 neutrons, 2 electrons in the first shell and 4 electrons in the second shell, labeled accordingly.
• Part 2:
• 1. Element's symbol, atomic number, atomic mass, and sometimes name; A group is a vertical column with similar chemical properties due to same valence - electron number, a period is a horizontal row with changing properties as number of protons/electrons increases; hydrogen, oxygen, nitrogen
• 2. (For oxygen) Atomic number 8, atomic mass approximately 16.00, non - metal, essential for respiration and used in combustion, makes up about 21% of Earth's atmosphere.
• Part 3:
• 1. Synthesis, decomposition, single - replacement, double - replacement, combustion
• 2. \(2H_2 + O_2

ightarrow 2H_2O\), \(2Na+Cl_2
ightarrow 2NaCl\), \(C_3H_8+5O_2
ightarrow 3CO_2 + 4H_2O\)