Answer:
Electronegativity generally increases from left to right across a period,
Explanation:
The true statement from the given choices is that electronegativity generally increases from left to right across a period.
Electronegativity is the measure of the relative tendency with which an atom of the element attract valence electrons in a chemical bond.
Across a period electronegativity increases from left to right and decreases down the group.
This is due to reduction in metallic properties as we move across the period from left to right.
Answer:Reliability
Explanation:
Reliability of a test refers to how consistently a test measures a characteristic under the same conditions.
Reliability can be defined as the degree of consistency of which a chemical test gives a similar result. measure. A test is said to be highly reliable when it gives the same repeated result under the same conditions of measure.
But when a test gives different results under the same condition of measure it has a low reliability.
Hence, If a test yields consistent results every time it is used, it has a high degree of reliability.
Answer:
0.14 M
Explanation:
To determinate the concentration of a new solution, we can use the equation below:
C1xV1 = C2xV2
Where C is the concentration, and V the volume, 1 represents the initial solution, and 2 the final one. So, first, the initial concentration is 1.50 M, the initial volume is 55.0 mL and the final volume is 278 mL
1.50x55.0 = C2x278
C2 = 0.30 M
The portion of 139 mL will be the same concentration because it wasn't diluted or evaporated. The final volume will be the volume of the initial solution plus the volume of water added, V2 = 139 + 155 = 294 mL
Then,
0.30x139 = C2x294
C2 = 0.14 M
Mean: the average. you have to add the values of the numbers and then divide by the amount of numbers there are. a common mistake to avoid is forgetting to divide the numbers at the end or subtracting them instead of adding.
mean: the middle number. you would first need to order the numbers from least to greatest. a common mistake to avoid is finding the middle number before ordering it from least to greatest
these two can also be commonly mistaken for one another because of the similar spelling.
