Answer:
Each student will need;
1 red jelly bean, 1 white jelly bean, 1 black jelly bean and 3 red jelly beans.
Explanation:
Sodium bicarbonate molecule, NaHCO3, or baking soda is composed of the following:
1 atom of sodium, Na;
1 atom of hydrogen, H;
1 atom of carbon, C, and
3 atoms of oxygen.
For each of the models to be built by the two students, these atoms are to be represented accordingly.
Since Red jelly beans represent sodium atoms (Na), white jelly beans represent hydrogen atoms (H), black jelly beans represent carbon atoms (C), and blue jelly beans represent oxygen atoms (O), each student will need;
1 red jelly bean, 1 white jelly bean, 1 black jelly bean and 3 red jelly beans.
A sample model is found in the attachment below:
<span>Melting is an endothermic process (i.e. it absorbs heat), whereas freezing is an exothermic process (i.e. it releases heat, or can be thought of, albeit incorrectly from a thermodynamics standpoint, as "absorbing cold"). The standard enthalpy of fusion of water can be used for both scenarios, but standard enthalpy is in units of energy/mass, so 10 times as much energy will be absorbed in the former scenario (melting 10 kg of ice) than what will be absorbed in the latter scenario (freezing 1 kg of water). For both processes, assuming the water is pure and at standard atmospheric pressure, and the entire mass remains at thermal equilibrium, the temperature of both the solid and the liquid will remain at precisely 0 degrees Celsius (273 K) for the duration of the phase change.</span>
Answer:
The time required for the coating is 105 s
Explanation:
Zinc undergoes reduction reaction and absorbs two (2) electron ions.
The expression for the mass change at electrode 
is given as :
where;
M = molar mass
Z = ions charge at electrodes
F = Faraday's constant
I = current
A = area
t = time
also; = 
; replacing that into above equation; we have:
---- equation (1)
where;
A = area
d = thickness
= density
From the above equation (1); The time required for coating can be calculated as;
![[ \frac{20 cm^2 *0.0025 cm*7.13g/cm^3}{65.38g/mol}*2 \frac{moles\ of \ electrons}{mole \ of \ Zn} * 9.65*10^4 \frac{C}{mole \ of \ electrons } ] = (20 A) t](https://tex.z-dn.net/?f=%5B%20%5Cfrac%7B20%20cm%5E2%20%2A0.0025%20cm%2A7.13g%2Fcm%5E3%7D%7B65.38g%2Fmol%7D%2A2%20%5Cfrac%7Bmoles%5C%20of%20%5C%20electrons%7D%7Bmole%20%5C%20of%20%5C%20Zn%7D%20%2A%209.65%2A10%5E4%20%5Cfrac%7BC%7D%7Bmole%20%5C%20of%20%5C%20electrons%20%7D%20%20%5D%20%3D%20%2820%20A%29%20t)
= 105 s
Answer:
52 amu
Explanation:
To get the relative atomic mass of the element, we need to take into consideration, the atomic masses of the different isotopes and their relative abundances. We simply multiply the percentages with the masses. This can be obtained as follows:
[89/100 * 52] + [8/100 * 49] + [3/100 * 50]
46.28 + 3.92 + 1.5 =51.7 amu
The approximate atomic mass of element x is 52 amu
Answer:
Explanation:
<u>Calculation of the mass of chromium as:-
</u>
Moles = 1.002 moles
Molar mass of chromium = 51.9961 g/mol
The formula for the calculation of moles is shown below:
Thus,
<u>Calculation of the mass of neon as:-
</u>
Moles = 
moles
Molar mass of neon = 20.1797 g/mol
Thus,
