Answer: Be= 2, C =4, Li = 1 and B=3
Explanation:
The valence shell can be define as the outermost shell of an atom that contains the valence electrons.
Beryllium (Be), electronic configuration; 1s2 2s2, = 2 electrons in its valence shell.
Carbon (C), electronic configuration; 1s2 2s2 2p2, = 4 electrons in its valence shell.
Lithium (Li), electronic configuration; 1s2 2s1 = 1 electron in its valence shell.
Boron (B) , electronic configuration; 1s2 2s2 2p1 = 3 electron in its valence shell.
Answer:
Large-scale natural disasters
Explanation:
The emergency situation that rescue workers could be in that would make it difficult for them to get energy to their electrical devices is "Large-scale natural disasters"
Large-scale natural disasters are very destructive and devastating. Their impact and effect can range from destruction of infrastructures, properties, social amenities and even ecosystems. When such disasters break out, they destroy things and which leads to difficulty in accessing certain amenities. Rescue workers even find it difficult to access energy for their electrical devices - because there is power outage.
Some of these large-scale natural disasters are earthquakes, tornadoes, hurricanes, floods, etc.
Answer:
K⁺ (aq) + F⁻ (aq) + H⁺ (aq) + Cl⁻ (aq) → KCl (aq) + H⁺ (aq) + F⁻ (aq)
Explanation:
KF (aq) + HCl (aq) → KCl (aq) + HF (aq)
KF (aq) → K⁺ (aq) + F⁻ (aq)
HCl (aq) → H⁺ (aq) + Cl⁻ (aq)
KCl (aq) → K⁺ (aq) + Cl⁻ (aq)
HF (aq) → H⁺ (aq) + F⁻ (aq)
Answer:
1.3×10⁻³ M
Explanation:
Hello,
In this case, given the dissociation reaction of acetic acid:

We can write the law of mass action for it:
![Ka=\frac{[H_3O^+][CH_3CO_2^-]}{[CH_3CO_2H]}](https://tex.z-dn.net/?f=Ka%3D%5Cfrac%7B%5BH_3O%5E%2B%5D%5BCH_3CO_2%5E-%5D%7D%7B%5BCH_3CO_2H%5D%7D)
Of course, excluding the water as heterogeneous substances are not included. Then, in terms of the change
due to the dissociation extent, we are able to rewrite it as shown below:

Thus, via the quadratic equation or solve, we obtain the following solutions:

Obviously, the solution is 0.00133M which match with the hydronium concentration, thus, answer is: 1.3×10⁻³ M in scientific notation.
Regards.
I don’t know about 3 but I know that 4 is solid, 5 is you’ll feel the vibration first, 6 is you’ll see the lightning first because the speed of light is faster than the speed of sound and 7 is sound waves need a medium to travel and light waves don’t, sound waves are longitudinal and light waves are transverse, and sound waves are mechanical waves while light waves are electromagnetic waves