Chemistry, 09.03.2021 23:10, LindaCat78

Name: Period:
Mole Unit Assessment
01. We observed the following reaction in the Reaction in a Bag activity:
CaCl, (aq) + 2NaHCO, (aq) + phenol red (basic form) -
Caco, (s) + 2NaCl (aq) + H20 (aq) + CO2 (aq) + phenol red (acidic form)
What are the reagent(s) in this reaction?
What are the product(s) in this reaction?

Answers: 3

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Answers

answered: Guest

c (diamond),

sio2 (quartz)

answered: Guest

assuming that your periodic table has eighteen columns, you should highlight the four elements in the third column from the left of the table.

explanation

neutral atoms of elements after calcium contain d electrons. the energy of d orbitals of a particular main shell lies between the energy of the s and p orbitals of the next main shell. for example, electrons in the $3d$ have energy higher than those in the $4 s$ orbital while lower than those of the $4 p$ orbital.

by the aufbau principle, electrons fill orbitals one at a time, starting from those of the lowest energy. the $4s$ orbital is therefore filled right after $3p$ orbitals and before $3 d$ orbitals.

potassium has electron configuration $[\text{ar}] 4 s^{1}$ and calcium $[\text{ar}] 4 s^{2}$ . the s orbital of a main shell holds a maximum of two electrons. the next element would thus have the electron configuration $[\text{ar}] 4 s^{2} \; 3d^{1}$ and satisfy the requirements.

a neutral atom of the element contains three electrons on top of the most recent noble gas element. it should thus be placed in the third column of the periodic table. both scandium and yttrium would satisfy the conditions. an aufbau diagram indicates that the 4f orbital is filled before the 5d. however, it appears that exceptions exists for both lanthanum and actinium. neutral atoms of the two d-block elements also demonstrate the $ns^{2} \; (n-1) p^{1}$ and should be highlighted as well.

answered: Guest

Conservation efforts have been effective in "increasing the number of endangered species, reducing all the negative impacts of human activity, and preserving wildlife habitats".hope my answer has you : )

answered: Guest

Answer

it is the minimum amount of material needed to sustain a fission reaction.

explanation

critical mass is the minimum amount of fissionable material that must be assembled for a sustained fission reaction to take place. although two to three neutrons are produced for every fission, not all of these neutrons are available for continuing the fission reaction. if the conditions are such that the neutrons are lost at a faster rate than they are formed by fission, the chain reaction will not be self-sustaining. at the point where the chain reaction can become self-sustaining, this is referred to as critical mass.