Answer:
Scandium
Explanation:
Mendeleev played an important role in the development of the modern periodic table. His periodic table was filled with gaps. He said that these gaps were elements that were yet to be discovered. He rightly predicted many elements which have now been discovered and fitted in their proper places in the periodic table.
He used the prefix ''eka'' to refer to elements whose properties were alike but were yet to be discovered at that time.
The compound named ekaboron which he predicted to have an atomic weight between 65 (zinc) and 75 (arsenic) with a valence similar to aluminum was later discovered in 1879 and properly named scandium.
Answer:
The average of given values is 2.1221 ml
Explanation:
Given data:
Given measurements = 3.00 ml , 2.0 ml, 2.987 × 10⁻³ml , 3.4856 ml
Average value of given measurements = ?
Solution:
Formula:
Average value = sum of all measurement / total number of measurements
2.987 × 10⁻³ml = 0.002987 ml
Now we will put the values.
Average value = 3.00 ml + 2.0 ml + 0.002987 ml+ 3.4856 ml / 4
Average value = 8.488587 ml / 4
Average value = 2.1221 ml
The average of given values is 2.1221 ml
Increasing every day. in 2013, we had about 7.125 Billion. in 9160, we had closer to 3 billion. It is still on a pretty steady clime today.
Answer:
IV
Explanation:
The complete question is shown in the image attached.
Let us call to mind the fact that the SN1 mechanism involves the formation of carbocation in the rate determining step. The order of stability of cabocations is; tertiary > secondary > primary > methyl.
Hence, a tertiary alkyl halide is more likely to undergo nucleophilic substitution reaction by SN1 mechanism since it forms a more stable cabocation in the rate determining step.
Structure IV is a tertiary alkyl halide, hence it is more likely to undergo nucleophilic substitution reaction by SN1 mechanism.
