Answer:
They all have the same number of protons but different numbers of neutrons.
Explanation:
These are called isotopes. Isotopy is the existence of two or more atoms of the same element having the same atomic number but different mass numbers due to the differences in the number of neutrons in their various nuclei.
The atomic number is the number of protons in an atom. For a neutral atom, it is the same as the number of electrons.
The mass number is the number of protons and neutrons in an atom.
silicon-28 (28Si)
silicon-29 (29Si)
silicon-30 (30Si)
All of these isotopes have an atomic number of 16
Now let us chech for the neutrons:
Number of neutrons = mass number - atomic number:
for silicon-28 (28Si) : 28-16 = 12 neutrons
silicon-29 (29Si)
: 29-16 = 13 neutrons
silicon-30 (30Si): 20-16 = 14 neutrons.
The answer is "<span>They have similar chemical properties and the same number of valence electrons."</span>
Answer:
2578.99 years
Explanation:
Given that:
100 g of the wood is emitting 1120 β-particles per minute
Also,
1 g of the wood is emitting 11.20 β-particles per minute
Given, Decay rate = 15.3 % per minute per gram
So,
Concentration left can be calculated as:-
C left =
Where,
is the concentration at time t
is the initial concentration
Also, Half life of carbon-14 = 5730 years
Where, k is rate constant
So,
The rate constant, k = 0.000120968 year⁻¹
Time =?
Using integrated rate law for first order kinetics as:
So,
<u>t = 2578.99 years</u>
Answer:
55.1 g Si.
Explanation:
Hello there!
In this case, for the given mole-mole relationship, it is possible to set up the following mole ratio as the moles of Si and P are the same:
1 mol Si = 1 mol P.
Next, since one mole of silicon has a mass of 28.09 g and one of phosphorous of 31.0 g, we can set up the following expression for the mass of silicon:
Therefore, the result is 55.1 grams of silicon.
Best regards!