Answer:
Single replacement is a reaction in which one element reacts with another compund to form another compound and another element.
planation:
In the question, the number of atoms per unit cell is required for:
A) Polonium (Po)
In polonium, the structure is simple cubic, meaning there are 8 corner atoms, which add up to one atom per unit cell.
B) Manganese (Mn)
The structure of the Mn can be considered to be a body centered cubic (BCC) and the number of atoms for this is 8 corner atoms and 1 central atoms, making a total of 2 atoms per unit cell.
C) Silver (Ag)
Silver has a face centered cubic (FCC) unit cell structure, where there are 8 corner atoms and 6 atoms on the faces, so there are a total of 4 atoms per unit cell.
Answer:
Method 1 - precision
Method 2 - accuracy
Method 3 - precision
Method 4 - accuracy
Explanation:
The accuracy of a method refers to how close the experimental result is to the accepted value. Accuracy could be checked by carrying out the required test on the standard and not on the sample or by adding a known amount of analyte to the sample so that the results obtained can be carefully compared.
Precision on the other hand, refers to how close the results of a replicate analysis are to each other. In testing for precision, the analysis must be carried out several times, in order to check how close the results are to each other.
<em>Answer:</em>
- The halogens have electron configurations that end in ns2np5.
<em>Explanation:</em>
<em>Halogen: </em>The elements of group 17 of periodic table are halogens like F, Cl, Br, I etc. They have 7 valence shells electrons. The electronic configurations of each halogen is given as follow
- F = [He]2s∧2 2p∧5
- Cl = [Ne] 3s∧2 3p∧5
- Br = [Ar] 4s∧2 3d∧10 4p∧5
- I = [Kr]5s∧2 4d∧10 5p∧5
From electronic configurations, it is cleared only halogens have valence shell elctrons in ns∧2 np∧5.
<em>Transition elements: </em>In transitions elements , electronic configuration ended in d- orbital.
<em>Inner transition elements:</em> In transitions elements , electronic configuration ended in f- orbital.
<em>Nobel gases</em>: Nobel gases elements have complete valence shells, Eight electrons like this ns2np6.
