Answer: 55
Explanation: A atom consists of a nucleus and electrons.Nucleus contain neutrons with no charge and protons with positive charge. The electrons bearing negative charge revolve around the nucleus.
An electrically neutral atom contains equal number of protons and electrons. Thus if a neutral element X contains 55 protons, it also contains 55 electrons.
D. uranium: atomic number 92, mass 238, neutrons 146
238-92=146
First, we need to convert the grams of gold into mole using the molar mass (molecular weight) of gold, and then into particles using avogadro's number (1 mol= 6.02 x 10^23)
molar mass of gold= 197 grams/ mole
100.0 grams (1 mole/ 197 grams) x (6.02 x 10^23 particles/ 1 mole) = 3.06 x 10^23
Answer: <span>B. Each element has a unique arrangement of electrons.
Explanation:
1) Since the number of electrons in neutral atoms is equal to the number of protons, and the number of protons are unique for each element, each element has a unique arrangement of electrons.
2) The spectrum of an element is the radiation emitted for the atoms of the element when the valence electrons are emitted and that depended on the electrons configuration.
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