The element first discovered in the sun is the element Helium. This noble gas is the second most abundant element<span> in the universe and was </span>discovered<span> on the </span>sun<span> before it was discovered on the earth. Helium is the result of the nuclear fusion of hydrogen creating thus the mass of energy in the sun.</span>
Answer:
The correct option is;
D. (2)(56 g)
Explanation:
MgCl₂ + 2KOH → Mg(OH)₂ + 2KCl
From the balanced chemical reaction equation, we have;
One mole of MgCl₂ reacts with two moles of KOH to produce one mole of Mg(OH)₂ and 2 moles of KCl
Therefore, the number of moles of KOH that react with one mole of KCl = 2 moles
The mass, m, of the two moles of KOH = Number of moles of KOH × Molar mass of KOH
The molar mass of KOH = 56.1056 g/mol
∴ The mass, m, of the two moles of KOH = 2 moles × 56.1056 g/mol = 112.2112 grams
The amount in grams of KOH that react with one mole of MgCl₂ = 112.2112 grams ≈ 112 grams = (2)(56 g).
Answer: 20 + 1 + 3.8 + 2.4 +27 = 54.2
Explanation: 20 gallons plus 1 gallon plus 3.8 plus 2.4 plus 27 equals to a total number of 54.2 gallons for the propane.
Answer:
The correct option is the second option
Explanation:
Generally, the aim of science is to understand a particular concept in the best and the most correct way possible; hence experiments are done and repeated to ensure an explanation is actually true about a concept or need modification.
The atomic models have also been a "beneficiary" of this process. The different atomic models are usually been improved upon as scientists leaned more. For example, the Dalton's atomic theory has been modified to a more correct atomic description; some of which are shown below
(1) Dalton's theory suggested that an atom is the smallest unit of a molecule. We know now from different experiments (by J. J Thompson and Rutherford) that atoms are not the smallest molecules and are made up of smaller particles known as protons, neutrons and electrons.
(2) Dalton's theory suggested that atoms of the same elements are alike in all aspects. The knowledge of isotopy shows this is not always the case. As atoms of the same elements (isotopes) have the same atomic number but different mass number; hence cannot be said to be the same in all aspects.
(3) Dalton's theory also suggested that when atoms react, they do so in fixed, simple whole number ratio. The knowledge of organic chemistry shows atoms do not always react in simple whole number ratios
There are several modifications to different postulations by scientists that have also occurred aside from this, hence the most correct answer is that "As scientists learned more, they modified the atomic model"
Answer:
compounds
Explanation:
Substances made of two or more elements that are chemically joined together are called <u>compounds</u>.
<em>Generally, elements are substances that contain just a type of atom. Compounds, on the other hand, contain different atoms (of different elements) that are chemically linked together. The linkage is referred to as bonding. The bonding could be covalent, ionic, or hydrogen bonding.</em>
