Answer: The transition elements are in the d-block, and in the d-orbital have valence electrons. They can form several states of oxidation and contain different ions. Inner transition elements are in the f-block, and in the f-orbital have valence electrons.
Explanation:
Answer:
The correct answer is 25 mL graduated cylinder (it should be used in all the cases)
Explanation:
In order to measure 25.00 ml sample of a solution it should be used a 25 mL graduated cylinder, as it is previously and properly calibrated. The other laboratory glassware, beaker and erlenmeyer, have graduations which are approximate, so they are used when exact volumes are not needed.
ii) graduated cylinder has the least uncertainly. It is more accurate than a beaker or erlenmeyer (to within 1%)
iii) A 25 mL graduated cylinder should be used because it is the most accurate lab glassware (between those were mentioned: beaker, erlenmeyer).
Answer:
The discipline of Earth and space science is concerned with the study of the planets and stars is
A. Astronomy
Explanation:
A.Astronomy:
'Astron' means stars and 'nomos' means laws. So astronomy is the study of stars , planets and space
B.
biology
It is derived from Greek word : 'Bios' means life and 'logos' means study.
Biology is study of life, living organism ,structure of organisms,evolution
C.Geology
It is the earth science which includes the study of rocks and solid earth, what it is made of and how it has changed .
D. Oceanography
It is the study of physical and biological aspects of oceans
Moles are the division of the mass and the molar mass. The moles of mercury (ii) oxide in the decomposition reaction needed to produce oxygen are 0.781 moles.
<h3>What is a decomposition reaction?</h3>
A decomposition reaction is a breakdown of the reactant into simpler products. The decomposition of mercury (ii) oxide can be shown as:
2HgO(s) → 2Hg(l) + O₂(g)
From the reaction, it can be said that 2 moles of mercury (ii) oxide decomposes to produce 1 mole of oxygen.
The moles of oxygen that needs to be produced are calculated as:
Moles = mass ÷ molar mass
= 12.5 gm ÷ 32 gm/mol
= 0.39 moles
0.39 moles of oxygen are needed to be produced.
From the stoichiometric coefficient of the reaction, the moles of HgO is calculated as: 2 × 0.39 = 0.781 moles
Therefore, 0.781 moles of HgO are required in the reaction.
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