The third answer because there are two of each atom
The two main types of bonds formed between atoms are ionic bonds and covalent bonds. An ionic bond is formed when one atom accepts or donates one or more of its valence electrons to another atom. A covalent bond is formed when atoms share valence electrons.
Answer:
31.7 °C
Explanation:
Charles law states that for volume of a gas is directly proportional to the absolute temperature for a fixed amount of gas at constant pressure
we can use the following equation
V1/T1 = V2/T2
where V1 is volume and T1 is temperature at first instance
V2 is volume and T2 is temperature at second instance
temperature should be in kelvin scale
T1 - 0 °C + 273 = 273 K
substituting the values in the equation
22.4 L / 273 K = 25.0 L / T2
T2 = 304.7 K
temperature in celcius is - 304.7 K - 273 = 31.7 °C
the gas must be 31.7 °C to reach a volume of 25.0 L
Answer:
The correct answer is:
<em>(1) It is important that the sample is dissolved in just enough hot solvent. </em>
Explanation:
The process of recrystallization is important to eliminate the impurities and to obtain better crystals of the solid. The solvent used to perform the recrystallization must have a high dissolution power of the substance to be recrystallized and a low dissolution power of the impurities. This is in order to eliminate most impurities. Furthermore, <em>It is important that the sample is dissolved in just enough hot solvent </em>because this should be easy to remove after the recrystallization and the crystal should form easily when the solution cools. Also, it is better to add the hot solvent to solubilize the crystals and keep the impurities insoluble, instead of adding the cold solvent and heating the solution. Additionally, the process of cooling the solution must be done slowly to obtain large and fewer crystals. A fast ice-cooling will form smaller crystals.
Answer is: cesium sulfide.
Formula for ionic compound is: Cs₂S.
Ionic compound <span>electrically </span>neutral, cesium has charge +1 (2· (+1) = +2) and sulfur has charge -2.
Cesium sulfide is whide powder, soluble in water, pyrophoric in dry air, reductant.