Answer:
On the left side of calcium atom.
Explanation:
There are two dots are present on the left side of calcium atom which represents the unpaired electrons present in the outermost shell. This structure is presented by Lewis in order to show the number of unpaired electrons in the atom. if the calcium atom loses these two electron during a chemical reaction so the two dots disappear and the calcium atom is now stable.
Answer:
Volume occupied by 55.5 moles of water gas at STP = 1240 Liters.
Explanation:
1st keep in mind that 'volume' in the context of problems like this apply only to the gas phase form of the substance. Water in solid form (ice) or liquid form (liquid water) do not apply. Volume in this case is referred to as 'molar volume' and is a gas occupying 22.4 liters at STP conditions (0°C, 1Atm).
So, if 1 molar volume of water gas (steam) occupies 22.4 Liters at STP, then 55.5 moles of water gas occupies 22.4 Liters/mole x 55.5 moles = 1243.2 Liters, or 1240 Liters (3 sig. figs.). :-)
Answer:
Correct answer is b) convex mirror
Explanation:
A convex mirror, which bulges outward, reflects at a wider angle near its edges than at its center, creating a slightly distorted image that's smaller than actual size. Convex mirrors have many uses. The smaller size of the images means that you can see more with these surfaces, hence their use in safety mirrors.
6 - one sodium atom, 1 hydrogen atom, 1 carbon atom, and 3 oxygen atoms.
Heat = 1.74 kJ
<h3>Further explanation</h3>
Given
melts at 328 ℃ + 273 = 601 K
mass = 23 g = 0.023 kg
initial temperature = 297 K
Final tmperature = 702 K
Required
Heat
Solution
1. raise the temperature(297 to 601 K)
c of lead = 0.130 kJ/kg K
Q = 0.023 x 0.13 x (601-297)
Q = 0.909 kJ
2. phase change(solid to liquid)
Q = m.Lf (melting/freezing)
Q = 0.023 x 23 kj/kg = 0.529 kJ
3. raise the temperature(601 to 702 K)
Q = 0.023 x 0.13 x (702-601)
Q = 0.302 kJ
Total heat = 1.74 kJ
