Answer:
The order of reactivity of metals is as follows, Potassium > Sodium > Lithium > Calcium > Magnesium > Aluminium > Zinc > Iron > Copper > Silver > Gold.
Explanation:
The reactivity of elements (metals) towards water decreases towards the right in a period. It also increases down the group. But zinc is more reactive towards water than iron. Hence the correct order is:
Iron<Zinc<Magnesium<Sodium
Atomic number is same as the number of protons in the element which is further equal to the number of electrons. As the number of electrons increases in the element, the atomic number of the element also increases.
In periodic table, elements are arranged in the groups, and these groups are columns starting from 1 to 18, elements are arranged in increasing order of atomic number. Elements are placed with difference of one atomic number.
First four elements present in the periodic table is:
atomic number is one (1).
atomic number is two (2).
atomic number is three (3).
atomic number is four (4).
Thus, the series of atomic numbers that represents the ordering of consecutive elements within the periodic table is the last option - 1, 2, 3, 4...
Answer:
Adding 1 mol of NaCl to 1 kg of water lower the vapor pressure of water <em><u>to the same extent</u></em> by adding 1 mol of
to 1 kg of water.
Explanation:
1) Moles of NaCl ,
Mass of water = m= 1 kg = 1000 g
Moles of water = 
Vapor pressure of the solution = 
Vapor pressure of the pure solvent that is water = 
Mole fraction of solute(NaCl)= 



The vapor pressure for the NaCl solution at 17.19 Torr.
2) Moles of sucrose ,
Mass of water = m = 1 kg = 1000 g
Moles of water = 
Vapor pressure of the solution = 
Vapor pressure of the pure solvent that is water = 
Mole fraction of solute ( glucose)= 



The vapor pressure for the glucose solution at 17.19 Torr.
p = p' = 17.19 Torr
Adding 1 mol of NaCl to 1 kg of water lower the vapor pressure of water to the same extent by adding 1 mol of
to 1 kg of water.
C because its meters right