Answer: option D - The total number of nucleons changes.
Explanation:
Nuclear Reaction is best described as a process such as the fission of an atomic nucleus, or the fusion of one or more atomic nuclei and / or subatomic particles in which the NUMBER of PROTONS and / or NEUTRONS in a nucleus CHANGES; the reaction products may contain a different element or a different isotope of the same element.
Note that the NUCLEONS refers to ONE of the subatomic particles of the atomic nucleus, i.e. a PROTON or a NEUTRON.
So, in a Nuclear reaction, the total number of nucleons changes.
Solids have a definite shape, and a definite volume.
Liquids have a definite volume, but have no definite shape.
Gas have neither a definite volume nor a definite shape.
Hope this helps!
Answer: pure substances.
Explanation:
The given substances are:
All what surrounds us, which has mass and occupies spaces, is matter. There are two kind of matter: pure substances and mixtures.
Pure substances have a uniform and constant composition. On the other hand, mixtures are combinations of two or more pure substances in any arbitratry ratio.
Pure substances may be elements or compounds. The elements are the substances conmposed by one only kind of atom. In the list of substances given, Li and O₂ are elements: all the atoms in Li are lithium, and all the atoms in O₂ are oxygen atoms.
Compounds are the chemical combination of two or more different kind of atoms. In the given list H₂O₂ and NaCl are compounds. As you see, H₂O₂ contains atoms of hydrogen and oxygen, chemically bonded, in a fixed ratio (2 atoms of hydrogen by 2 atoms of oxygen). And NaCl has atoms of Na (sodium) and Cl (chlorine), chemicaly bonded, in a fixed ratio (1:1).
There are only 118 known elements and you can find them in any modern periodic table. Therer are virtually infinitely many compounds since many different combinations of the elements can be attained.
Elements and compounds have in common that they are classified as pure substances.
Respiring while swimming underwater
Because anaerobic respiration means respiration with no oxygen, and there is no oxygen underwater
