The relation between molecular (formula) mass and molar mass Page 4 4 • To obtain one mole of copper atoms (6.02 x 1023 atoms), weigh out 63.55 g copper. The molar mass (M) of a substance is the mass of one mole of entities (atoms, molecules, or formula units) of the substance.
Answer:
Group 1: alkali metals, or lithium family.
Group 2: alkaline earth metals, or beryllium family.
Group 3: the scandium family.
Group 4: the titanium family.
Group 5: the vanadium family.
Group 6: the chromium family.
Explanation:
Answer : Option C) Atomic Size
Explanation : The atomic radius of the elements is found to be decreasing if we go from left to right in the modern periodic table. Accordingly,
increases as the number of shielding electrons present in the atomic nucleus of the periodic elements which lies in the same row remains constant while the number of protons in each atomic shell increases.
The effective nuclear charge
of an atom is defined as the net positive charge which is felt by the valence electron of the atomic element.
When
is observed to decrease, it is seen that the atomic radius grows in size. So, it explains the inverse relationship between both. This phenomenon occurs, because there is more screening of the electrons from the nucleus taking place, which is observed due to decrease the attraction between the electron and the nucleus.
Answer:
-3.617 °C
Explanation:
Step 1: Given data
Mass of water (m): 210.0 g
Energy released in the form of heat (Q): -3178 J (the minus sign corresponds to energy being released)
Specific heat of water (c): 4.184 J/g.°C
Temperature change (ΔT): ?
Step 2: Calculate the temperature change
We will use the following expression.
Q = c × m × ΔT
-3178 J = 4.184 J/g.°C × 210.0 g × ΔT
ΔT = -3.617 °C