The reaction is extremely exothermic, producing a bright yellow light and a great deal of heat energy.
Answer: -
C. The hydrogen at 10 °C has slower-moving molecules than the sample at 350 K.
Explanation: -
The kinetic energy of gas molecules increase with the increase in the temperature of the gas. With the increase in kinetic energy, the gas molecules also move faster. Thus with the increase of temperature, the speed of the molecules increase.
Temperature of first hydrogen gas sample is 10 °C.
10 °C means 273+10 = 283 K
Thus first sample temperature = 283 K
The second sample temperature of the hydrogen gas is 350 K.
Thus the temperature is increased.
So both the kinetic energy and speed of molecules is more for the hydrogen gas sample at 350 K.
Thus the hydrogen at 10 °C has slower-moving molecules than the sample at 350 K.
Hence the answer is C.
Explanation:
12)
a) Sodium + oxygen = ?
When sodium reacts oxygen its forms sodium oxide as a product.

b) magnesium + fluorine = ?
When magnesium reacts with fluorine its forms magnesium fluoride as a product.

13)
a) 
Decomposition of mercury(II) oxide on heating gives out mercury and oxygen gas.
b)
The electrolytic decomposition of water gives out hydrogen gas amd oxygen gas.
Amount of silver nitrate taken = 269.μmol 
Volume of the solution = 300. mL
Concentration of a solution is generally expressed in terms of molarity. Molarity is defined as the moles of a substance present per liter of the solution.

We want the concentration in millimoles/L.
Converting μmol to millimol solute:
μ
= 0.269 millimol
Volume from mL to L: 
Therefore concentration of the chemist's solution = 
Answer:
YES
Explanation:
SO3 2-DOES show delocalized bonding
delocalized bonding occurs when there is a resonance structure and the electronic bonds are a delocalised "cloud" around the species
The resonance effect of the sulfite sructures ithe folowing link:
https://www.chemistryscl.com/general/lewis-resonance-structure-of-SO32-/index.php