To determine how much of a 144g sample of carbon-14 will remain after 1.719 x 10^4 years, you can use the formula for exponential decay:
\[N(t) = N_0 \cdot \left(\frac{1}{2}\right)^{\frac{t}{T}}\]
Where:
- \(N(t)\) is the remaining amount after time \(t\).
- \(N_0\) is the initial amount.
- \(t\) is the time that has passed.
- \(T\) is the half-life.
In this case, \(N_0\) is 144g, \(t\) is 1.719 x 10^4 years, and \(T\) is the half-life of carbon-14, which is 5,730 years.
Plug these values into the formula:
\[N(t) = 144g \cdot \left(\frac{1}{2}\right)^{\frac{1.719 \times 10^4\text{ years}}{5,730\text{ years}}}\]
Now, calculate:
\[N(t) = 144g \cdot \left(\frac{1}{2}\right)^{\frac{3}{2}}\]
\[N(t) = 144g \cdot \left(\frac{1}{2} \cdot \frac{1}{2} \cdot \frac{1}{2}\right)\]
\[N(t) = 144g \cdot \frac{1}{8}\]
Now, multiply 144g by 1/8 to find the remaining amount:
\[N(t) = \frac{144g}{8} = 18g\]
So, after 1.719 x 10^4 years, only 18g of the 144g sample of carbon-14 will remain.
B) atomic number
C) number of protons
D) number of electrons
The quantity that can vary among atoms of the same element is the mass number, which represents the sum of the number of protons and neutrons in an atom.
The quantity that can vary among atoms of the same element is the mass number. The mass number represents the sum of the number of protons and neutrons in an atom. While the atomic number (which represents the number of protons) remains constant for atoms of the same element, the number of neutrons can vary, resulting in different mass numbers for atoms of the same element.
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11. Consider the elements neon, bromine, and phosphorus. Which has five electrons in its 4p sublevel?
I just did it, the correct answer is actually D. They are experimentally determined exponents.
Answer : Silicon dioxide, , is a covalent compound.
Explanation :
Covalent compound : It is a compound in which the bonds are formed by the equal sharing of electrons. The bonds are formed between two non-metals.
Ionic compound : It is a compound in which the bonds are formed by the complete transfer of electrons.
In the silicon dioxide , the silicon and the oxygen atom is a non-metals and the bonds are formed between silicon and oxygen non-metal atoms are the covalent bonds.
Hence, the silicon dioxide, , is a covalent compound.