To perform this test to check if gold is real, make a light, tiny scratch on the item using a small nail file. Choose a spot that is not noticeable if possible. Use a dropper to apply a small drop of nitric acid to the scratch. If there is no reaction, then the piece is probably made from real gold.
Osmosis of Water Across the Membrane. Osmosis is the tendency for water molecules to move from where there is a higher concentration to where there is a lower one. ... The cell membrane helps to regulate and slow down the flow of water into the cell. This is yet another way that the cell membrane helps maintain homeostasis
Answer:
What is the largest sediment that can be transported by a stream that has a velocity of 50 cm/sec?What is the largest sediment that can be transported by a stream that has a velocity of 50 cm/sec?
Sand is the only sediment that could be transported at that velocity as others are heavy to be transported with the mentioned velocity
Explanation:
When testing a hypothesis, scientists use repeated trials and replication to make sure that they get the same answer each time, and that it isn't just a lucky guess the first time. They need be sure that the answer to their hypothesis is 100% the same every time.