Answer: [B]: 12.0 .
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Note: The pH scale ranges from 1 to 14 .
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The light reflected from the surface of the Moon takes only a second to reach Earth. The Sun is more than 8 light-minutes away. And so, if the light from the nearest star (Alpha Centauri) takes more than 4 years to reach us, we're seeing that star 4 years in the past.
Answer:
<h3>Burning, cooking, rusting and rotting are examples of chemical changes.</h3>
Given:
rate = k [A]2
concentration is
0.10 moles/liter
rate is 2.7 × 10-5 M*s-1
Required:
Value of k
Solution:
rate = k [A]2
2.7 × 10-5 M*s-1
= k (0.10 moles/liter)^2
k = 2.7 x 10^-3
liter per mole per second
Answer:
The halogens located in group 17
Explanation:
The change in energy of a neutral atom when an electron is added is known as electron affinity. <em>Fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At) are known as halogens and conform the group 17 of the periodic table, the group that presents higher electron affinity.</em> This characteristic happens because of their atomic structures, it is easier for them to gain electrons because they are closer to form octets.
Here I present you halogens' electron affinities values:
- Fluorine (F) -328 kJ mol-1
- Chlorine (Cl) -349 kJ mol-1
- Bromine (Br) -324 kJ mol-1
- Iodine (I) -295 kJ mol-1
<em>The use of negative signs is to indicate the RELEASE of energy.</em>
I hope you find this information useful and interesting! Good luck!