Answer: A) Sodium Na and Magnesium Mg
Explanation:
In the period table, you can see that Sodium (group 1) has 11 protons, and Magnesium (group 2) has 12 protons. 11+12=23 protons
Answer:
-250.3kJ
Explanation:
Based in the reactions and using -<em>Hess's law-</em>:
(1) P₄(s) + 6 Cl₂(g) → 4PCl₃(g) ΔH₁ = -4439kJ
(2) 4PCl₅(g) → P₄(s) + 10Cl₂ ΔH₂ = 3438kJ
The sum of (1) + (2) is:
4PCl₅(g) → 4PCl₃(g) + 4 Cl₂ ΔH = -4439kJ + 3438kJ = -1001kJ
Dividing this reaction in 4:
PCl₅(g) → PCl₃(g) + Cl₂ ΔH = -1001kJ / 4 = <em>-250.3kJ</em>
The population would decrease, the more predators there are the more food needed for the species .
<span>Out of the following given choices;</span>
<span>a. cliff b. fault </span>
<span>c. plateau d. mountain</span>
<span>The answer is
b. A divergent boundary is a line at which two tectonic plates are moving away from each other. It is caused by the two magma convection currents in the mantle moving in opposing directions (one clockwise, the other anti-clockwise) hence dragging the crust with them. Therefore the biggest force at the boundary on the crust is that of pulling. This causes <span>fractures and faults on the earth’s crust.</span></span>
Avogadro's number is defined as the number of elementary particles (molecules, atoms, compounds, etc.) per mole of a substance. It is equal to 6.022×1023 mol-1 and is expressed as the symbol NA.
