The two strands of a DNA molecule must be separated
Answer:
if you are working with hazardous materials.
Explanation:
A properly operating and correctly used fume hood can reduce or eliminate exposure to volatile liquids, dusts, and mists. It is advisable to use a laboratory hood when working with all hazardous substances.
Answer : Option 1) nuclei of
and nuclei of
only.
Explanation : Radiation is spontaneously emitted from nuclei of
because this isotope of hydrogen is highly radioactive as compared to other isotopes of hydrogen namely; nuclei of
and nuclei of
.
They have much stable nucleus as compared to nuclei of
.
The more it is unstable the more radiations will be emitted from its nucleus.
Answer: Option (4) is the correct answer.
Explanation:
A mixture is defined as a substance that contains two or more different substance that are physically mixed with each other.
If solute particles are evenly distributed in a solvent then it is known as a homogeneous mixture.
For example, salt dissolved in water is a homogeneous mixture.
If solute particles are unevenly distributed into the solvent then it is known as a heterogeneous mixture.
For example, sand in water is a heterogeneous mixture.
Thus, we can conclude that the statement a mixture must contain at least two different substances, is correct about mixtures.
Answer:
C. 1.3 mol
Explanation:
PV = nRT
where P is absolute pressure,
V is volume,
n is number of moles,
R is universal gas constant,
and T is absolute temperature.
Given:
P = 121.59 kPa
V = 31 L
T = 360 K
R = 8.3145 L kPa / mol / K
Find: n
n = PV / (RT)
n = (121.59 kPa × 31 L) / (8.3145 L kPa / mol / K × 360 K)
n = (3769.29 L kPa) / (2993.22 L kPa / mol)
n = 1.26 mol
Round to two significant figures, there are 1.3 moles of gas.