Explanation:
Number of Cm neutrons = 242 - 96 = 146
Answer:
The answer is A, the cell.
Explanation:
Cells are the basic units of structure and function in living organisms.
Answer:
Explanation:
We are given this compound with the formula: C₃H₂O
According the subscripts, 1 molecule contains 3 carbon atoms, 2 hydrogen atoms, and 1 oxygen atom.
We can make a ratio. There are 3 carbon atoms for every 1 molecule of C₃H₂O.
Since we want to calculate the number of atoms in 200 molecules, we can multiply the ratio by 200.
200 molecules of C₃H₂O contains 600 atoms of carbon.
Answer:
% = 76.75%
Explanation:
To solve this problem, we just need to use the expressions of half life and it's relation with the concentration or mass of a compound. That expression is the following:
A = A₀ e^(-kt) (1)
Where:
A and A₀: concentrations or mass of the compounds, (final and initial)
k: constant decay of the compound
t: given time
Now to get the value of k, we should use the following expression:
k = ln2 / t₁/₂ (2)
You should note that this expression is valid when the reaction is of order 1 or first order. In this kind of exercises, we can assume it's a first order because we are not using the isotope for a reaction.
Now, let's calculate k:
k = ln2 / 956.3
k = 7.25x10⁻⁴ d⁻¹
With this value, we just replace it in (1) to get the final mass of the isotope. The given time is 1 year or 365 days so:
A = 250 e^(-7.25x10⁻⁴ * 365)
A = 250 e^(-0.7675)
A = 191.87 g
However, the question is the percentage left after 1 year so:
% = (191.87 / 250) * 100
<h2>
% = 76.75%</h2><h2>
And this is the % of isotope after 1 year</h2>
Answer:
8 electrons (e-)
Explanation:
In the atom of every elements, there are three sub-atomic particles namely: protons, electrons, and neutrons. The protons are the positively charged particles, the electrons are negatively charged while the neutrons are neutrally charged.
In an uncharged or neutral atom i.e. charge 0, the number of protons is always equal to the number of electrons because they cancel each other out. When a difference occurs in the number of these particles, the atom becomes charged i.e. an ion. According to this question, oxygen atom (O) contains 8 positively charged protons, this means that it also contains 8 negatively charged electrons in its atom.