Answer:
Explanation:
We are asked to find how many moles are in 4.8 × 10²³ fluorine atoms. We convert atoms to moles using Avogadro's Number or 6.022 × 10²³. This is the number of particles (atoms, molecules, formula units, etc.) in 1 mole of a substance. In this case, the particles are atoms of fluorine.
We will convert using dimensional analysis and set up a ratio using Avogadro's Number.
We are converting 4.8 × 10²³ fluorine atoms to moles, so we multiply the ratio by this number.
Flip the ratio so the units of atoms of fluorine cancel each other out.
Condense into 1 fraction.
Divide.
The original measurement of atoms has 2 significant figures, so our answer must have the same. For the number we found, that is the hundredths place. The 7 in the thousandths tells us to round the 9 in the hundredths place up to a 0. Then, we also have to round the 7 in the tenths place up to an 8.
4.8 × 10²³ fluorine atoms are equal to <u>0.80 moles of fluorine.</u>
<u>Answer:</u> The correct option is A) They have fixed energy values.
<u>Explanation:</u>
Electron is one of the sub-atomic particle present around the nucleus of an atom which is negatively charged.
In an atomic model, it is assumed that the electron revolves around the nucleus in discrete orbits having fixed energy levels.
These electrons when jumping from one energy level to another, some amount of radiation is either emitted or absorbed.
These fixed energy levels are given by the Bohr model and thus, the electrons are quantized.
Hence, the correct option is A) They have fixed energy values.
Answer:
atomic number
Explanation:
atomic number is the number of protons
A bicycle rusting after it is left in the rain is an example of a chemical reaction because it involves oxidation (Option d).
<h3>What is a chemical reaction?</h3>
A chemical reaction can be defined as a phenomenon in which one or more substances called reactants react to form one or more different compounds, which are known as products.
A chemical reaction may include an enzyme that works to increase the seed of the reaction in normal conditions by lowering the activation energy of the reaction.
Therefore, we can conclude that a chemical reaction such as oxidation in a bicycle is a process where reactants combine or break down to form the products of such reaction.
Complete question:
Which of the following situations contains an example of a chemical reaction?
a. Ice forming after water is placed in a freezer
b. Watercolor paint drying on paper
c. a sugar cube dissolving in a glass of water
d. a bicycle rusting after it is left in the rain
Learn more about chemical reactions here:
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