The alpha particle is the helium nucleus.
The mass of helium nucleus (⁴₂He) is 4u.
The mass of radioactive atom decreases by 4u. Look at the reaction below:
²²³₈₈Ra ---> ⁴₂He + ²¹⁹₈₆Rn
<h2>Answer : Law of conservation of mass</h2><h3>Explanation :</h3>
The law of conservation of mass states that in any reaction mass is neither created nor lost it has to remain constant in a system.
In this case, when the reaction setup was done in normal way the mass was lost in surrounding was not considered nor being calculated; whereas when the reaction was studied in a closed system where the gas was collected after the reaction the mass changes was noted down which helped to prove the point of law of conservation of mass and energy.
One can consider an example of soda can where the carbonated drink contains pressurized carbon dioxide gas. when opened the gas bubbles gets lost into the surroundings and we don't measure the mass changes. Instead if the soda can was opened in such a way where the gas evolved was measured then the mass changed would remain the same.
a) NH₃ molecules have stronger intermolecular attractions than CH₄ molecules.
Explanation:
Ammonia molecules have stronger intermolecular attractions compared to methane.
Ammonia molecules have london dispersion forces and hydrogen bonds between their molecules.
Methane molecules have only london dispersion forces in their structure.
- hydrogen bonds are very strong attractive forces between molecules in which the hydrogen of a molecule is attracted by a more electronegative atom of another usually oxygen, nitrogen and fluorine.
- London dispersion forces are weak forces of attraction between heteronuclear atoms.
Learn more:
Hydrogen bonds brainly.com/question/10602513
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D. 1 proton and 1 neutron
Special Structures in Plant Cells. Most organelles are common to both animal and plant cells. However, plant cells also have features that animal cells do not have: a cell wall, a large central vacuole, and plastids such as chloroplasts.