Answer:
The ionic compound NaCl has a Face Centered Cubic unit cell
The site for atoms are Face, center and Edges corner.
Effective number of atoms
Na+
1centers + 12edges x
= 4 Na+
Cl-
6face x
+ 
x8 corners = 4Cl-
This is just one unit cell effective atom, there are thousand's of such unit cells are combined to form one such structure of NaCl. The real formula of NaCl is Na4Cl4 but for simplicity we use empirical formula that is NaCl.
<h3><u>Answer;</u></h3>
= 78 g of NaOH
<h3><u>Explanation;</u></h3>
Concentration = Moles of solute/Volume of solution
Thus;
Moles of the solute = Volume × Concentration
= 7.80 Moles/L × 0.250 L
= 1.95 moles
But; 1 mole of NaOH = 40.0 g
Thus;
Mass of NaOH = moles × molar mass
= 1.95 moles × 40 g/mole
<u> = 78 g of NaOH</u>
Answer:Ionic compounds form when positive and negative ions share electrons and form an ionic bond. ... The positive ion, called a cation, is listed first in an ionic compound formula, followed by the negative ion, called an anion. A balanced formula has a neutral electrical charge or net charge of zero.
Explanation:Simple ions:
Perchlorate ClO4- IO3-
Chlorate ClO3- BrO3-
Chlorite ClO2-
Hypochlorite OCl- OBr-
Answer:
A chemical change
Explanation:
The marshmallow turning brown and bubbling implies that a chemical change has taken place.
For chemical changes to occur, we observe any of the following:
- a new kind of matter is formed.
- it is always accompanied by energy changes
- the process is not easily reversible
- it involves a change in mass
- requires considerable amount of energy.
ii. Two signs that shows a chemical change has taken place is that:
- bubbles are being formed as it is roasted and it implies that new substances have been formed.
- also, significant amount of heat energy is supplied for the roasting.
