Answer:
Cu
Explanation:
Groups 3 - 12 (or groups IIA - IIB) of the periodic table contain transition elements. Transaction elements start from period four (4) of the periodic table. The phrase alludes to the fact that the d sublevel is filling at a lower main energy level than the s sublevel that came before it.
The transition elements' arrangement is inverted from the fill order, with the 4 s filled prior to the actual 3 d begins. The transition elements are commonly referred to as transition metals since they are all metals. They are less reactive than the metals in Groups 1 and 2 and have normal metallic characteristics.
From the options given Cu is the only transition metal in the fourth period on the periodic table.
Answer:
The natural phenomenon used to describe the length of a meter is the speed of light. The length of a meter is the length a light path travels in 1/(299792458) seconds through a vacuum.
The definition is better due to the uncertainty involved in the use of the length of a standard meter stick because the length of the meter stick could change due to atmospheric conditions from place to place
Explanation:
Answer:
1.Respiration of animals and plants.
2.The burning of fossil fuels.
3.Bacteria decompose corpses.
Out of the following given choice:
A. The increase in
the airspace occupied by vinegar molecules
B. The chemical reaction with nerves, which is slower than
other sensory processes
C. Attractive forces between the air and vinegar molecules
D. Random collisions between the air and vinegar molecules.
<span>The answer is
D. While the particles may be
moving at high velocities even at room
temperatures, the delay is due to the numerous collisions
between the vinegar molecules and the air molecules.This changes the vinegar’s
molecules directions from straight lines to random unpredictable paths</span>
Answer:
In the 1H NMR spectrum of ethanol three different signals are observed, this is due to the existence of 3 types of hydrogens with different chemical environment. Hydrogens A (3.57 ppm) are more screened than C (1.10 ppm) due to the presence of oxygen (electonegative atom that removes electron density). The chemical environment of hydrogen B (4.78 ppm), attached directly to oxygen, is also different by resonating at a frequency different from the previous ones.
The hydroxylic hydrogen produces a singlet, the pair of carbon hydrogens one give rise to a quadruplet and the three hydrogens of carbon two produce a triplet.
Explanation:
