Where is the rest of the question?
Answer:
The correct option is;
D. All the elements in families 1 and 2 can place all their shell electrons in the s sub-level
Explanation:
The elements in families 1 and 2 also called the group 1A and group 2A elements are known as the alkali and alkaline earth metals. The elements in the families 1 and 2 are also referred to as the s-block elements as they have their valence electrons which are 1 and 2 respectively, in the s-orbital or s sub-level
Due to their low ionization energy, and the ease with which they donate their valence electrons, elements of the families 1 and 2 are known to be very reactive, and are found in a combined state in nature.
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:
Mass = 357.7 g
Explanation:
Given data:
Mass of Fe = 250 g
Mass of oxygen = 120 g
Mass of iron(III) oxide produced = ?
Solution:
Chemical equation:
4Fe + 3O₂ → 2Fe₂O₃
Number of moles of Fe:
Number of moles = mass/molar mass
Number of moles = 250 g/ 55.8 g/mol
Number of moles = 4.48 mol
Number of moles of O₂ :
Number of moles = mass/molar mass
Number of moles = 120 g/ 32 g/mol
Number of moles = 3.75 mol
Now we will compare the moles of reactants with product.
Fe : Fe₂O₃
4 : 2
4.48 : 2/4×4.48 = 2.24
O₂ : Fe₂O₃
3 : 2
3.75 : 2/3×3.75= 2.5
Less number of moles of Fe₂O₃ are produced by Fe thus it will act as limiting reactant.
Mass of Fe₂O₃:
Mass = number of moles × molar mass
Mass = 2.24 mol × 159.69 g/mol
Mass = 357.7 g
Answer:
a reference book about weather
Explanation:
