4Al+6Fe(NO3)2= 6Fe+4Al(NO3)3
<span>I’ve answered this
question before so if these are the choices to the question presented:
An oxygen atom double-bonded to a carbon atom, with a hydrogen atom
single-bonded to the same carbon atom. </span><span>
<span>A hydrogen atom covalently bonded to an oxygen atom, which is
covalently bonded to a carbon in the carbon chain. </span>
<span>A carbon atom single-bonded between two other carbon atoms,
with an oxygen atom double-bonded to the central carbon atom as well. </span>
<span>An oxygen atom single-bonded between two carbon atoms within
a carbon chain.
Then, the answer would be “a hydrogen atom covalently bonded to an oxygen atom,
which is covalently bonded to a carbon in the carbon chain.<span>”</span></span></span>
Answer:
10. D
9. A
8. A or B
Explanation:
10. Calcium has 20 electrons, but the Calcium ion has 18 electrons.
9. The mass of electrons are negligible.
8. Electrons have a very small mass where some consider it to have no mass.
Answer:
It is true that earth was once covered with oceans and little dry land.
Explanation:
Over the course of around four billion years, the Earth's oceans have lost about a quarter of their original mass. Today the atmosphere is rich in oxygen, which reacts with both hydrogen and deuterium to recreate water, which falls back to the Earth's surface. So the vast bulk of the water on Earth is held in a closed system that prevents the planet from gradually drying out. According to the researchers, the continents emerged relatively suddenly from an ocean that covered 95 percent of the Earth's surface. The appearance of large masses of dry land would have caused more extreme weather, changes in ocean currents and the emergence of proper seasons. In turn, these environmental changes may have led to rise in atmospheric oxygen that enabled the explosion of new life forms around 500 million years ago.
If you move a substance from one container to another and its volume changes substances is gas.
