Question

a/an _______ is the smallest unit of matter that has the characteristics of a chemical element.
a) proton
b) atom
c) molecule
d) electron
question 20 (5 points)
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2.8 kg is equal to
a) 2.8 × 10⁶ dg
b) 2.8 × 10⁻⁶ mg
c) 2.8 × 10⁶ mg

Explanation:

Step1: Analyze the first question

An atom is the smallest unit of matter that has the characteristics of a chemical element. A proton is a sub - atomic particle within an atom. A molecule is made up of atoms. An electron is also a sub - atomic particle.

Step2: Analyze the second question

We know that \(1\space kg = 10^{6}\space mg\). So for \(2.8\space kg\), we use the conversion factor. If \(x\) is the mass in milligrams, then \(x=2.8\times10^{6}\space mg\) (since \(kg\) to \(mg\) conversion: \(1\space kg = 10^{3}\space g\) and \(1\space g= 10^{3}\space mg\), so \(1\space kg=10^{3}\times10^{3}\space mg = 10^{6}\space mg\)).

Answer:

For the first question: B. atom
For the second question: C. \(2.8\times 10^{6}\space mg\)