<span> strictly speaking, a molecule has at least two atoms. ... Atoms with full valence electron shells are stable. Full Text[ edit ] The noble gases are a group of chemical elements that make up Group 18 on the periodic table.</span>
<h3>
Answer:</h3>
89.88° C
<h3>
Explanation:</h3>
<u>We are given;</u>
- Mass of gold cylinder as 75 g
- specific heat of gold is 0.129 J/g°C
- Initial temperature of gold cylinder is 65°C
- Mass of water is 500 g
- Initial temperature of water is 90 °C
We are required to calculate the final temperature;
- We know that Quantity of heat is given by the product of mass, specific heat capacity and change in temperature.
<h3>Step 1: Calculate the quantity of heat absorbed by the Gold cylinder</h3>
Assuming the final temperature is X° C
Then; ΔT = (X-65)°C
Therefore;
Q = 75 g × 0.129 J/g°C × (X-65)°C
= 9.675X - 628.875 Joules
<h3>Step 2: Calculate the quantity of heat released by water</h3>
Taking the final temperature as X° C
Change in temperature, ΔT = (90 - X)° C
Specific heat capacity of water is 4.184 J/g°C
Therefore;
Q = 500 g × 4.184 J/g°C × (90 - X)° C
= 188,280 -2092X joules
<h3>Step 3: Calculate the final temperature, X°C</h3>
we know that the heat gained by gold cylinder is equal to the heat released by water.
9.675X - 628.875 Joules = 188,280 -2092X joules
2101.675 X = 188908.875
X = 89.88° C
Thus, the final temperature is 89.88° C
Answer:
C) 237.96682 amu
Explanation:
The symbol for neptunium-236 is given as;
²³⁶₉₃Np
This element has 93 protons and (236 - 93 = 143) neutrons.
Mass Number =Total mass of Protons + Total mass of neutrons
Total Mass pf protons = 93 * 1.007825 amu, = 93.727725 amu
Total mass of Neutrons = 143 * 1.008665 amu = 144.239095 amu
Mass = 144.239095 + 93.727725 = 237.96682 amu
Correct option is option C.
