In 1869, just five years after John Newlands put forward his law of octaves, a Russian chemist called Dmitri Mendeleev published a periodic table. Mendeleev also arranged the elements known at the time in order of relative atomic mass, but he did some other things that made his table much more successful.
i hope this helps in some way!
The definition for "What do you call two or more atoms bonded together" is a compound. Think of water. Water is called H20. Water is made of 2 hydrogen atoms and 1 oxygen atom. That is to atoms bonded together to make a compound which is water. Hope I helped
For the first question, salt is soluble while sand is insoluble or not dissolvable in water. The salt should have vanished or melted, but the sand stayed noticeable or visible, making a dark brown solution probably with some sand particles caught on the walls of the container when the boiling water was put in to the mixture of salt and sand. The solubility of a chemical can be disturbed by temperature, and in the case of salt in water, the hot temperature of the boiling water enhanced the salt's capability to melt in it.
For the second question, the melted or dissolved salt should have easily made its way through the filter paper and into the second container, while the undissolved and muddy sand particles is caught on the filter paper. The size of the pores of the filter paper didn’t change. On the contrary, the size of the salt became smaller because it has been dissolved which is also the reason why it was able to go through the filter paper, while the size of the sand may have doubled or even tripled which made it harder to pass through.
a.
A substance's specific heat tells you how much heat is required to increase the temperature of 1 g of that substance by 1°C.
The equation that establishes a relationshop between heat and change in temperature is
q = m • c • ∆T, where
q - heat absorbed
c - the specific heat of the substance, in your case of water
ΔT - the change in temperature, defined as the difference between the final temperature and the initial temperature
so:
q = 1.00 g • 4.18 J/g×°C • (75.0 - 38.5)°C
q = 152,57 J
just apply this formula for all exercises
