Answer:
rusting occur in oxygen and water coz when you put a nail into the water and you leave it three days you will the nail become brownish and that is due to oxygen and water
By law of conservation of energy, the amount of heat lost
by the metal should be equal to the amount of heat gained by water. That is,
the change in energy (expressed in enthalpies) should be equal:
- (ΔH)metal = (ΔH)water
Take note of the negative sign in front of (ΔH)metal, this
means that heat is lost by this metal.
Where ΔH or change in enthalpy is:
ΔH = m Cp (T2 – T1)
So,
- 15 g (Cp) (23 °C – 99 °C) = 75 g (4.18 J/g * °C) (26 °C –
23 °C)
1,140 Cp = 940.5
<span>Cp = 0.825 J/g * °C (ANSWER)</span>
About 4. the weight of He is about 4 amus and the weight of O is about 16 amus, so you would need 4 He atoms to get close to the same mass as an O atom. i hope this helps
Answer:
An area around a molecule that describes a region of space where the electrons that are shared between bonded atoms can reside
Explanation:
A molecular orbital is an area around a molecule that describes a region of space where the electrons that are shared between bonded atoms can reside.
Molecular orbitals are formed by linear combination of atomic orbitals of about the same energy. The number of atomic orbitals that are combined to give molecular orbitals is the same as the number of molecular orbitals formed. The build up of electrons in molecular orbitals also follow the Aufbau principle, Hund's rule and Pauli exclusion principle.
Answer:
- <u>The container must be built of lead, and it should be kept in a concrete vault.</u>
Explanation:
The goal is to contain the <em>gamma rays</em> to<em> reduce</em> the <em>exposure </em>to their harmful <em>radiation</em>.
The gamma rays are the most energetic electromagnetic radiation: they have the smallest wavelength, the largest frequency, and the largest energy from all the electromagnetic radiations.
Due to that, only very dense substances like lead and concrete can stop the gamma rays. In the case of concrete, large blocks with thick walls are required.
Thus, in a lab the best container for a sample of uranium - 238 that is decaying, emitting gamma rays, must be built of lead, and enclosed in a conrete vault.
