The density of the fresh water is less than the density of the salt water.
Smell. Density test. Reactivity test. PH test.
water doesn't burn
The answer depends on what you want tell it apart from!
well the male would have the male gonads and the female would have the female ones. You can tell them apart because the males would be outside the body.
Provided the apple looks and smells fresh and crisp (as though you would like to eat it) it should be OK to eat. Seawater itself will not harm the apple. Seawater is not a sterile environment. The apples might be OK or might not. There is no way to you to tell. If you are considering eating apples that have been involved in a flood, I would not recommend eating them.
The guys are usually bigger than the girls. == ==
it depends what you are telling apart
All acorns are the seed of oak trees (Quercus) there are many varieties and each variety has an individual identity so to tell them apart you would need to compare them together.
Taste and Look.
Gypsum is soluble in water - Talc isn't
This section of a drug monograph would tell you if the drug is soluble in water.
100gms 100gms ANSWER you can never tell how much salt is in a litre of seawater it varies where you are. the average salts is 35ppt (parts per thousand)