Question

1. practice: classification of matter

question 1
how would you calculate the atomic mass of an atom of silver (ag)?
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question 2
how does an atom differ from a molecule?
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question 3
the element lithium (li) has three protons and three electrons. the element fluorine (f) has nine protons and nine electrons. an atom of the element lithium (li) transfers an electron to an atom of the element fluorine (f). which type of bond results between the atoms, and what happens to the charges in each of the atoms?

Explanation:

Question 1

Step1: Identify isotopes and abundances

Silver has two stable isotopes, Ag - 107 and Ag - 109. We need to know their relative abundances.

Step2: Use atomic - mass formula

The atomic mass ($A$) of an element is calculated as $A=\sum_{i} (m_i\times a_i)$, where $m_i$ is the mass of isotope $i$ and $a_i$ is the relative abundance of isotope $i$. For silver, if the mass of Ag - 107 is $m_{107}$ and its abundance is $a_{107}$, and the mass of Ag - 109 is $m_{109}$ and its abundance is $a_{109}$, then $A = m_{107}\times a_{107}+m_{109}\times a_{109}$. The relative abundances of Ag - 107 and Ag - 109 are approximately 51.84% and 48.16% respectively, and the masses of the isotopes are close to their mass - numbers (107 u and 109 u).

An atom is the smallest unit of an element that retains its chemical properties. It consists of a nucleus (protons and neutrons) and electrons. A molecule is formed when two or more atoms are chemically bonded together. Atoms can be the same (e.g., $O_2$) or different (e.g., $H_2O$).

When lithium transfers an electron to fluorine, an ionic bond is formed. Lithium, after losing an electron, becomes a positively - charged ion ($Li^+$) as it has one more proton than electron. Fluorine, after gaining an electron, becomes a negatively - charged ion ($F^-$) as it has one more electron than proton.

Answer:

Calculate using the formula $A = m_{107}\times a_{107}+m_{109}\times a_{109}$ with known isotope masses and abundances.

Question 2