Answer:
I think the answer is D.coral reef, neritic zone
Explanation:
Answer:
Any element in group 18 has eight valence electrons (except for helium, which has a total of just two electrons
<span>a) 7.9x10^9
b) 1.5x10^9
c) 3.9x10^4
To determine what percentage of an isotope remains after a given length of time, you can use the formula
p = 2^(-x)
where
p = percentage remaining
x = number of half lives expired.
The number of half lives expired is simply
x = t/h
where
x = number of half lives expired
t = time spent
h = length of half life.
So the overall formula becomes
p = 2^(-t/h)
And since we're starting with 1.1x10^10 atoms, we can simply multiply that by the percentage. So, the answers rounding to 2 significant figures are:
a) 1.1x10^10 * 2^(-5/10.5) = 1.1x10^10 * 0.718873349 = 7.9x10^9
b) 1.1x10^10 * 2^(-30/10.5) = 1.1x10^10 * 0.138011189 = 1.5x10^9
c) 1.1x10^10 * 2^(-190/10.5) = 1.1x10^10 * 3.57101x10^-6 = 3.9x10^4</span>
Answer:
The atomic number of silicon is 14 while atomic mass of carbon is 14.
Explanation:
An atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.
All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example if neutral atom has 6 protons than it must have 6 electrons. The sum of neutrons and protons is the mass number of an atom while the number of protons are number of electrons is the atomic number of an atom.
In given atoms ¹⁴₆C and ²⁸₁₄Si the atomic mass of carbon is 14 while the atomic number of silicon is 14. It means silicon has 14 electrons or protons while carbon has 6 protons or electrons because its atomic number is 6. Carbon has 6 protons and 8 neutrons in its nucleus while silicon has 14 protons and 14 neutrons in its nucleus.
In C:
Number of neutrons + protons = 8 + 6 = 14 amu (mass number)
Number of electrons = 6
In Si:
Number of neutrons + protons = 14 + 14 = 28 amu (mass number)
Number of electrons = 14
<em>Answer:</em> 20 m/min east
<em>Explanation:</em> The speed is distance divided by time
distance between start-point and end-point = 100 meters
<em>time to cover the distan</em>ce = 5 minutes
100 m ÷ 5 min = 20 m/min east
y<u>ou have to add east since velocity is the measure of speed and direction and your answer needs to include the direction</u>
