A scientist is working with methane $(CH_4)$ and butane $(C_4H_{10})$. Which statement best compares these chemicals?
A. They are two different types of molecules that each contain the same number of atoms.
B. They are two different types of atoms that are each made up of a different number of elements.
C. They are compounds made of the same two elements, but each contain different numbers of atoms.
D. They are matter made of the same two compounds, but each contain different types of elements.
Answer (1)
Methane ( C H 4 ) and butane ( C 4 H 10 ) are analyzed.
The number of atoms in each molecule is counted: methane has 5, butane has 14.
Both molecules contain carbon and hydrogen.
The best statement comparing them is identified: They are compounds made of the same two elements, but each contain different numbers of atoms. T h ey a reco m p o u n d s ma d eo f t h es am e tw oe l e m e n t s , b u t e a c h co n t ain d i ff ere n t n u mb erso f a t o m s .
Explanation
Analyzing Composition Let's analyze the composition of methane ( C H 4 ) and butane ( C 4 H 10 ). Methane consists of one carbon atom and four hydrogen atoms, while butane consists of four carbon atoms and ten hydrogen atoms.
Counting Atoms Now, let's count the number of atoms in each molecule. Methane: 1 Carbon + 4 Hydrogen = 5 atoms. Butane: 4 Carbon + 10 Hydrogen = 14 atoms.
Identifying Elements Next, we identify the elements present in each molecule. Both methane and butane contain the elements carbon and hydrogen.
Comparing Statements Finally, we compare the number of atoms and the elements in each molecule to the given statements and choose the best one.
The first statement says they are two different types of molecules that each contain the same number of atoms. This is incorrect because methane has 5 atoms and butane has 14 atoms.
The second statement says they are two different types of atoms that are each made up of a different number of elements. This is incorrect because methane and butane are molecules, not atoms, and they are made up of the same elements.
The third statement says they are compounds made of the same two elements, but each contain different numbers of atoms. This is correct because both methane and butane are made of carbon and hydrogen, but they have different numbers of carbon and hydrogen atoms.
The fourth statement says they are matter made of the same two compounds, but each contain different types of elements. This is incorrect because methane and butane are compounds, not matter, and they are made of the same elements.
Conclusion Therefore, the best statement is: They are compounds made of the same two elements, but each contain different numbers of atoms.
Examples
Understanding the composition of molecules like methane and butane is crucial in various fields. For example, in environmental science, knowing the structure of methane helps scientists study its impact as a greenhouse gas. In chemistry, the different ratios of carbon and hydrogen in methane and butane explain their different properties, such as flammability and boiling points. This knowledge is also essential in designing efficient combustion engines and developing alternative fuels.
