Answer:
Name Atomic Number Electron Configuration Period 1 Hydrogen 1 1s1 Helium 2 1s2 Period 2 Lithium 3 1s2 2s1 Beryllium 4 1s2 2s2 Boron 5 1s2 2s22p1 Carbon 6 1s2 2s22p2 Nitrogen 7 1s2 2s22p3 Oxygen 8 1s2 2s22p4 Fluorine 9 1s2 2s22p5 Neon 10 1s2 2s22p6 Period 3 Sodium 11 1s2 2s22p63s1 Magnesium 12 1s2 2s22p63s2 Aluminum 13
Answer: 97
Explanation:
The element Ru is <u>Ruthenium</u> which has <u>44 protons</u>.
In this case, our atom is an isotope with <u>53 neutrons</u>.
With this information, we can use the mass number formula to find this atom's mass number.
mass number = protons + neutrons
mass number = <u>44 protons</u> + <u>53 neutrons</u>
mass number = <u>97</u>
<span>The water cycle has no starting point. But, we'll begin in the oceans, since that is where most of Earth's water exists</span>
Answer:
-1190.24 kJ
Explanation:
The enthalpy change in a chemical reaction that produces or consumes gases is given by the expression:
ΔH = ΔU + Δngas RT
where Δn gas is the change of moles of gas, R is the gas constant,and T is temperature.
Now from the given balanced chemical reaction, the change in number of mol gas is equal to:
Δn gas = mole gas products - mole gas reactants = 2 - 5/2 = -1/2 mol
Sionce we know ΔU and the temperature (298 K), we are in position to calculate the change in enthalpy.
ΔH = -1189 x 10³ J + (-0.5 mol ) 8.314 J/Kmol x 298 K
ΔH = -1.190 x 10⁶ J = -1.190 x 10⁶ J x 1 kJ/1000 J = -1.190 x 10³ J
Aluminum would be my best answer