Answer:
The Lewis dot diagram is supposed to have dots on each side. What's incorrect is that there isn't a dot on the bottom, only the left and right side and the top. What's correct about this is that there are 5 outer valence electrons, and they correctly put 5 dots, even though they're in the wrong place.
Explanation:
Answer:
D
Explanation:
Gamma radiation penetrates the cell wall of prokaryotic organisms such as bacteria and can inhibit their metabolic functions as well as destroy their DNA.
Debunking the other answers:
A is incorrect as Gamma radiation is used in the treatment of cancer via radiotherapy.
B is incorrect as Gamma rays are too small and would just penetrate any smoke particles.
C is incorrect because Gamma rays are used to disinfect food products to prevent food borne illness. Irradiation is safe to use on food and does not make it radioactive.
Thus, D is correct.
Answer:
They are all alkali earth metals.
Explanation:
Their valence shell each has 2 electrons. Also, they are all shiny, silvery-white, somewhat reactive metals at standard temperature and pressure. They form alkaline solutions, hydroxides, when reacting with water and their oxides are found in the earth’s crust.
Answer:
oxygen is limiting reactant
Explanation:
Given data:
Mass of phosphorus = 25.0 g
Mass of oxygen = 50.0 g
What is limiting reactant ?
Solution:
Chemical equation:
P₄ + 5O₂ → P₄O₁₀
Number of moles of P₄:
Number of moles = mass/molar mass
Number of moles = 25.0 g/ 123.89 g/mol
Number of moles = 0.20 mol
Number of moles of O₂:
Number of moles = mass/molar mass
Number of moles = 50.0 g/ 32 g/mol
Number of moles = 1.56 mol
now we will compare the moles of reactants with product:
P₄ : P₄O₁₀
1 : 1
0.20 : 0.20
O₂ : P₄O₁₀
5 : 1
1.56 : 1/5×1.56 = 0.312 mol
Less number of moles of product are formed by the oxygen thus it will act as limiting reactant.
Answer:
10 M
Explanation:
Molarity -
Molarity of a substance , is the number of moles present in a liter of solution .
M = n / V
M = molarity
V = volume of solution in liter ,
n = moles of solute ,
From the question,
V = 200mL
Since, 1L = 1000mL ,
1 mL = 0.001 L
Hence,
V = 200mL = 0.2 L
n = 2.0 mol
Hence, to calculate the molarity of the solution, the above formula can be used as -
M = n / V
M = 2.0 mol / 0.2 L = 10 M
