The initial temperature is 137.34 °C.
<u>Explanation:</u>
As the specific heat formula says that the heat energy required is directly proportional to the mass and change in temperature of the system.
Q = mcΔT
So, here the mass m is given as 23 kg, the specific heat of steel is given as c = 490 J/kg°C and the initial temperature is required to find with the final temperature being 140 °C. Also the heat energy required is 30,000 J.
ΔT =
ΔT =
Since the difference in temperature is 2.66, then the initial temperature will be
Final temperature - Initial temperature = Change in temperature
140-Initial temperature = 2.66
Initial temperature = 140-2.66 = 137.34 °C
Thus, the initial temperature is 137.34 °C.
Answer: when two elements combine, A and B, the ratio of the weight of B combining with A is always a whole number
Explanation:
Answer:
Pu-239
Explanation:
Beta decay moves the element which undergoes the decay one place to the right in the periodic table since to conserve charge and being beta radiations an electron we convert a neutron into a proton and an electron. In neutron capture we increase the atomic mas by one unit. We that in mind, lets solve the question:
U-238 + ₁⁰ n ⇒ U-239 ⇒ Np -239 + ₋₁⁰β ⇒ Pu-239 + ₋₁⁰β
Answer:
They are all the same = 8
Explanation:
Since the symbol of that atom is not give, we can infer from the given number the nature and kind of element we are dealing with.
The number 15.999 rounded up to 16 is the atomic weight of the atom also called the mass number.
Although not peculiar enough, we are certain that this atom is Oxygen.
On the periodic table, elements are arranged based on their atomic numbers.
Atomic number of oxygen = 8 = number of protons
For every neutral atom on the periodic table, the number of protons and electrons are the same
Atomic number of oxygen = number of protons = number of electrons = 8
Number of neutrons = Mass number - atomic number = 16 - 8 = 8
