Answer:
O₈¹⁷
Explanation:
An atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.
All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other.
In given statement there are 8 electrons it means the atomic number of given atom is 8 so it would oxygen. The atomic mass of oxygen is 16 while in given statement mass is 17 it means it is the isotope of oxygen that have one more neutron than oxygen 16.
Isotope of an element have same atomic number but different atomic mass due to different number of neutrons.
Put the salt and sand in some water.
the salt will not be visible but the sand will
now strain the the sand from the water
now boil the water and now the water will boil away and now you will just have salt left.
The reason the mass did not change because he did not add anything to the mixture accept the two liquids and its not possble to change the mass/ weight of any certain weighted item like the which is heavier the 1 pound of feathers or the 1 pound of bricks the only things is that the brick has more density so there for neither one is heavier than the other because the are both a pound
Answer:
D
Explanation:
Recall that entropy measures the number of microstates in a substance, which is highest in gases, followed by liquids and solids. Hence, entropy increases if the products have more gaseous molecules than the reactants.
- In reaction one, chlorine gas is converted into solid NaCl, so entropy decreaes.
- In reaction two, four moles of gas are converted into two moles of gas, so entropy decreases.
- In reaction three, ice is melted to form water, which has higher entropy. Thus, entropy increases.
- In reaction four, a liquid is freezed into its solid phase, leading to a decrease in entropy.
- In reaction five, oxygen gas is converted into solid MgO, so entropy decreases.
In conclusion, the answer is D.
