Answer:
Explanation:
In all calorimetric experiment , the calorimeter must be isolated from the surrounding . Otherwise the heat change in the experiment can not be determined with precision .
The reaction is endothermic . Hence, there is lowering of temperature due to absorption of heat in the reaction equal to ΔH°. The value of ΔH° can be calculated by measuring fall in the temperature of the content . The fall in the temperature will be less when heat is allowed to come from the surrounding . Less fall of temperature will result in less ΔH° to be calculated .
Hence in the given experiment , if the student neglects to put lid on the cup , the experiment will give less value of ΔH°.
The reaction is a synthesis…
… because <em>two substances are combining to make one other substance</em>.
It is also a <em>reduction-oxidation reaction</em> because the <em>oxidation number of Al increases</em> from 0 to +3 and the <em>oxidation number of O</em> decreases from 0 to -2.
Answer:
they all have one common function which is to pump blood and Arteries carry blood away from the heart; the main artery is the aorta. ... Capillaries carry blood away from the body and exchange nutrients, waste, and oxygen with tissues at the cellular level. Veins are blood vessels that bring blood back to the heart and drain blood from organs and limbs.
Explanation:
Answer:
Josue
Explanation:
J.J Thompson proposed the plum pudding model of the atom. In his proposition, the atom is a sphere of positive charges into which negative charges were embedded. This model of the atom did not significantly contribute to our present day understanding of atomic structure.
On the other hand Ernest Rutherford laid out the foundation for a more accurate understanding of atomic structure in his nuclear model of the atom. According to Rutherford, the atom consists of a positively charged massive core called the nucleus around which electron move in orbits. His idea was akin to the solar system with the sun at it's core and planets moving around the sun in orbits.
This his idea of the nuclear theory was held as fundamentally correct by Neils Bohr's model of the atom. Hence, his nuclear theory of the atom was a significant milestone in our present day understanding of atomic structure.
Answer:
One billion
Explanation:
A nanometer is a BILLIONTH of a meter which means it takes one billion to equal a meter
