<u>Answer:</u>
<em>Atomic number 75 is dedicated to an element named rhenium and has been given Re as its chemical name.</em>
<u>Explanation:</u>
With a really low concentration it is one of the rarest metals that is found in Earth's crust.
Like all other elements rhenium also has certain isotopes among with 185 and 187 are the most stable ones. Hence these two are the ones that are naturally available abundance is 34% and 63% respectively.
When 3.66 g of KOH (∆Hsol = -57.6 kJ/mol) is dissolved in 150.0 mL of solution, it causes a temperature change of 5.87 °C.
The enthalpy of solution of KOH is -57.6 kJ/mol. We can calculate the heat released by the solution (Qr) of 3.66 g of KOH considering that the molar mass of KOH is 56.11 g/mol.
According to the law of conservation of energy, the sum of the heat released by the solution of KOH (Qr) and the heat absorbed by the solution (Qa) is zero.
150.0 mL of solution with a density of 1.02 g/mL were prepared. The mass (m) of the solution is:
Given the specific heat capacity of the solution (c) is 4.184 J/g･°C, we can calculate the change in the temperature (ΔT) of the solution using the following expression.
When 3.66 g of KOH (∆Hsol = -57.6 kJ/mol) is dissolved in 150.0 mL of solution, it causes a temperature change of 5.87 °C.
Learn more: brainly.com/question/4400908
Answer:
B. Distributed over a very wide range
D. Limited life existence in geologic time.
Explanation:
Index fossils are very unique fossils that helps in determining the relative ages of rocks and biostratigraphic correlation. They are usually called guide fossils.
- Fossils are the preserved remains of dead organisms found in rocks.
- Index fossils are a special class of fossils with the following properties;
- They are widely distributed.
- They have a short stratigraphic range.
- They show rapid evolution trends
The number of protons in the nucleus of the atom is equal to the atomic number (Z). The number of electrons in a neutral atom is equal to the number of protons.
Answer is: <span>the objects potential energy is 24500 J.
</span>m(object) = 50 kg.
h(object) = 50 m.
g = 9,8 m/s².
E(object) = m·g·h.
E(object) = 50 kg · 9,8 m/s² · 50 m.
E(object) = 24500 N·m = 24500 J = 24,5 kJ.
g - <span>the acceleration of free fall.
mg - </span><span>weight of the object.</span>
