Answer:
0.50 moles of Cu
Explanation:
The balanced chemical equation for given synthetic reaction is,
2 Cu + S → Cu₂S
According to balance chemical equation,
1 mole of Cu₂S is produced by = 2 moles of Cu
So,
0.25 moles of Cu₂S will be produced by = X moles of Cu
Solving for X,
X = 0.25 mol × 2 mol / 1 mol
X = 0.50 moles of Cu
Hence, as the molar ratio of Cu to Cu₂S is 2:1 hence, to produce 0.25 moles of Cu₂S we will need 0.50 moles of Cu.
Answer:
D 1 and 3 only I am not sure
Explanation:
By the object's composition and the acting agent to which factors the change of the substance or entity.
<span>The effect of physical property of matter on the object or substance can be better identified when the object doesn't change in composition or in nature. Unlike chemical property which has changed in its composition and atomic structure that was caused by chemical change or reaction due to an agent. Physical property is identified thru physical reactions or changes that has never changed the object in an atomic level, like cutting paper into smaller sizes. The aforementioned example illustrates physical proerty but being cut into smaller buts without changing the object from paper to any other substance, thus, its structure remain and its still called paper regardless of size, mass and texture. <span>
</span></span>
Answer:
stay the same.
Explanation: Period 3 consists of the full 1s, 2s, and 2p electron orbitals, plus the 3s and 3p valence orbitals, which are filled with a total of 8 more electrons as we move from left (Na) to the far right (Ar):
Na: 1s2 2s2 2p6 3s1
Ar: s2 2s2 2p6 3s2 3p6
As we move from left to right, and ignoring the already-filled 1s, 2s, and 2p orbitals, the period three starting and ending elements have the following:
Na: 3s1
Ar: 3s2, 3p6
All the new electrons electrons filled the third energy level (3s and 3p). So the energy level does not change, just the orbitals.
