This is an exception to the general electronegativity trend. It can be explained by looking at the electron configurations of both elements.
<span>Be:[He]2<span>s2
</span></span><span>B:[He]2<span>s2</span>2<span>p1
</span></span>
When you remove an electron from beryllium, you are taking away an electron from the 2s orbital. When you remove an electron from boron, you are taking an electron from the 2p orbital. The 2p electrons have more energy than the 2s, so it is easier to remove them as they can more strongly resist the effective nuclear charge of the nucleus.
Answer:
Answer below.
Explanation:
An exothermic reaction is a chemical reaction that releases energy through light or heat. It is the opposite of an endothermic reaction. Expressed in a chemical equation: reactants → products + energy.
Answer: Evaporation
Explanation:
When the heat of the sun touches the water, the water molecules heat up and move gradually faster. Over time molecules start to pop out the surface of the water individually.
And then eventually all the water is evaporated into water vapor.
Answer:
0.84ppm
Explanation:
Mass of solute = 3.8 x 10⁻⁴g
Mass of solution = 450g
Unknown is the concentration in ppm; parts per million
The parts per million is one of the units of representing small concentration of solutes in a solution.
Solutes are the substances dissolving in another to give solution.
Here the concentration is expressed in a million units.
Concentration in ppm = 
x 10⁶
= 
x 10⁶
= 0.84ppm
