Answer:
Answers are in parentheses.
In the Bohr model of the atom, the electrons move in fixed, (circular) paths around a dense positively-charged nucleus. On the other hand, the quantum mechanical model shows the probability of finding an electron as a (cloud) of negative charge.
Answer:
2 and 3 because there are the protons and neutrons which have a greater mass than the electrons which are found in the locations 1 and 4. The atom contains a nucleus, which is made from protons and neutrons, and electrons which are found around the nucleus. The mass of the atoms is concentrated in the very tiny space represented by the nucleus. Of course the electrons have a mass too, but is very small compared to the protons and neutrons, and we usually neglect its mass.
Option B, C and D are correct.
<h3><u>Explanation:</u></h3>
Carbon is a non metallic element with the atomic number 6 and mass number 12. Whereas oxygen is also a non metallic element with the atomic number 8 and mass number of 16.
In carbon monoxide, the mass ratio of oxygen to carbon is 16:12 =1.33. This ratio is same for every sample of carbon monoxide, because carbon monoxide has the universal formula of CO.
Similarly In carbon dioxide , the mass ratio of oxygen to carbon is 32:12 =2.667. This ratio is same for every sample of carbon dioxide, because carbon dioxide has the universal formula of 
.
Even we can see that the mass ratio of oxygen to carbon in carbon dioxide is just twice the mass ratio of oxygen to carbon in carbon monoxide, because of presence of twice as much as oxygen per molecule of carbon dioxide than carbon monoxide.
Answer:
No
Explanation:
<em>No. </em>T<em>he demonstration does not violate the conservation of mass.</em>
<u>The law of conservation of mass states that mass can neither be created nor destroyed in a reaction. However, mass can be converted from one form to another during the reaction.</u>
In this case, even though the remaining bits of paper weigh 0.5 g while the original paper weighed 2.5 g, the ashes and smoke/gas from the burning will all add up to the lost weight of the paper.
<em>The burned part has been converted into other forms. If the smoke/gas and the ashes are properly captured, they will mark up with the weight of the remaining paper to give the weight of the original paper. </em>
Answer:
helium
Explanation:
By losing an electron, they look like the noble gas that immediately precedes them on the periodic table.
