Answer: Option (4) is the correct answer.
Explanation:
Activation energy is the minimum amount of energy required by the reactants to participate in the chemical reaction.
Therefore, reactant molecules whose energy is less than the activation energy are not able to participate in the reaction. Hence, a catalyst lowers the activation energy so that molecules with less energy can also participate in the reaction.
Thus, a catalyst is a specie that increases the reaction rate and has a lower activation energy.
Answer:
a tropical strom is when theres a lot of rain and it almost developed into a hurricane and a thunderstorm is rain with lightning and thunder but not that bad like a tropical storm and a tornado is when there is a huge gust of win that is formed in a circle like shape and could cause damage to homes
Explanation:
Answer:
They have the same number of electron energy levels.
They transition from a metal to noble gas.
Explanation:
Periods in the periodic table of elements refer to elements in the same row. All the elements in a certain row of the periodic table;
have the same number of electron energy levels.
transition from a metal to noble gas.
Answer: 0.8M
Explanation:
Given that,
Amount of moles of NaCl (n) = ?
Mass of NaCl in grams = 1.40 g
For molar mass of NaCl, use the molar masses:
Sodium, Na = 23g;
Chlorine, Cl = 35.5g
NaCl = (23g + 35.5g)
= 58.5g/mol
Since, amount of moles = mass in grams / molar mass
n = 1.40g / 58.5g/mol
n = 0.024 mole
Now, given that:
Amount of moles of NaCl (n) = 0.024
Volume of NaCl solution (v) = 30.0mL
[Convert 30.0mL to liters
If 1000 mL = 1L
30.0mL = 30.0/1000 = 0.03L]
Concentration of NaCl solution (c) = ?
Since concentration (c) is obtained by dividing the amount of solute dissolved by the volume of solvent, hence
c = n / v
c = 0.024 mole / 0.03 L
c = 0.8 M (0.8M means concentration is in moles per litres)
Thus, the concentration of the solution is 0.8M
Answer:
1s² 2s²2p³
Explanation:
If the atom has seven electrons, it is Element 7 (nitrogen).
In the Periodic Table, you count the electrons in all the subshells up to
No. 7.
In the first Period, you have filled the 1s level (2 electrons).
In the second Period, you have filled the 2s subshell (2 electrons) and put three electrons in the 2p subshell.
Thus, the electron configuration is
1s² 2s²2p³
Note how the superscripts tell you the number of electrons in each subshell: <em>2 + 2 + 3 = 7</em>.
