Answer:
Hygroscopic
Explanation:
An hygroscopic substance is one that absorbs moisture from the atmosphere and becomes wet. Their ability to remove water from air is less than that of deliquescent substances. Most of the solid hygroscopic substances forms pasty substances and not solutions like the deliquescent compounds.
Examples are sodium trioxonitrate(v), copper(ii) oxide e.t.c
Efflorescence compounds gives off their water of crystallization to the atmosphere.
Answer:
-<em>9</em><em>.</em><em>6</em><em>7</em><em>5</em>
Explanation:
<em>c</em><em>o</em><em>r</em><em>r</em><em>e</em><em>c</em><em>t</em><em> </em><em>m</em><em>e</em><em> </em><em>i</em><em>f</em><em> </em><em>i</em><em>m</em><em> </em><em>w</em><em>r</em><em>o</em><em>n</em><em>g</em><em>.</em><em>!</em><em>!</em><em> </em><em />
To find the net ionic equation we must first write the balanced equation for the reaction. We must bear in mind that the reagents Ca(NO3)2 and Na2S are in the aqueous state and as product we will have CaS in the solid state, since it is not soluble in water and NaNO3 in the aqueous state.
The balanced equation of the reaction will be:

Ca(NO3)2(aq) + → Ca(aq) + 2Na(s)NO3Now, c(aq)ompounds in the aqueous state can be written in their ionic form, so the reaction will transform into:Na2S +

So, the answer will be option A
INFORMATION:
We must find the number of valence electrons for magnesium
STEP BY STEP EXPLANATION:
In order to know the number of valence electrons for Mg, we need to locate the element in the periodic table
Since Mg is in the second group of the periodic table, it has two valence electrons.
ANSWER:
B) 2
Answer:
HX (aq) + H₂O (l) ⇄ H₃O⁺ (aq) + X⁻ (aq)
Acid Base Conj. acid Conj. base
Explanation:
The equation is:
HX (aq) + H₂O (l) ⇄ H₃O⁺ (aq) + X⁻ (aq)
This is the typical equilibrium for a weak acid. It would complete if we notice the Ka.
HX (aq) + H₂O (l) ⇄ H₃O⁺ (aq) + X⁻ (aq) Ka
1 mol of hypothetic HX acid react to 1 mol of water in order to release a proton and make hydronium and generate the X⁻ anion.
HX will be the acid, in this case a weak one and water will be the base. Water is able to accept a proton to make itslef hydronium
Hydronium is the conjugate acid.
The X⁻ will be the conjugate strong base.
This ion can generate the acid form again, that's why it is strong, because it can make hydrolisis.
X⁻ (aq) + H₂O (l) ⇄ HX (aq) + OH⁻(aq) Kb
In this case, the anion will be the conjugate base which it takes a proton from water (acid form) to make a conjugate acid, the HX and a conjugate base, OH⁻