Answer:
The correct answer is C. element
Explanation:
The sample cannot be an element because an element - or <em>elemental substance</em> - cannot be decomposed into simpler substances. Thus, it cannot be composed by differents types of atoms. For example, an element is carbon (C).
As the sample contains <u>three types of atoms</u>, it can be a compound, a molecule or a mixture, because they can be composed by different types of atoms - of different chemical elements. For example, the sample could contain the element carbon (C) combined with other elements, for example oxygen (O) or hydrogen (H), amoing others.
Answer:
The hydroxide [OH-] concentration of the solution is 1.26*10⁻⁵ M.
Explanation:
The pOH (or potential OH) is a measure of the basicity or alkalinity of a solution.
POH indicates the concentration of hydroxyl ions [OH-] present in a solution and is defined as the negative logarithm of the activity of hydroxide ions (that is, the concentration of OH- ions):
pOH= -log [OH-]
A solution has a pOH of 4.90. Replacing in the definition of pOH:
4.90= -log [OH-]
Solving:
-4.90= log [OH-]
1.26*10⁻⁵ M= [OH-]
<u><em>The hydroxide [OH-] concentration of the solution is 1.26*10⁻⁵ M.</em></u>
While the Moon and Mercury have relatively small volcanoes, those on Venus, Earth and Mars are large and numerous. Earth's volcanoes are still active and Venus' may be, but scientists debate whether Mars' volcanic activity has finished.
Answer:
13) Carbon Dioxide and water
Explanation:
The fact is that during photosynthesis, Carbon Dioxide is needed by green plants to manufacture their food and water is also needed but also chloroplast which contained chlorophyll is also needed
hence, the options are somehow confusing
14) perhaps it should be all of the above
Explanation:
proton normally = atomic number
protons = 9
