<span>All molecules are made up of atoms.
N2 O2 and H2 exist in molecule form and not in atomic form.
They exist freely in nature as molecules.
According to above explanation,
</span><span>B. Some elements found in nature exist as molecules, is the correct answer.</span>
Answer:
Exothermic reaction: In exothermic reaction, energy is transferred to the surroundings, and the surrounding temperature increases, this is known as exothermic reaction. In other words energy exits in exothermic reaction. Some example of exothermic reactions are:
1) Neutralisation reaction.
2) Combustion reaction.
3) Some oxidation reaction.
Endothermic reaction: In endothermic reaction, energy is taken in from the surrounding, and the surrounding temperature decreases, this is known as endothermic reaction. In other words energy enters in endothermic reaction. Some example of exothermic reactions are:
1) Thermal decomposition.
2) Reaction between citric acid and sodium hydrogen carbonate.
Answer:
Mathematically, symmetry means that one shape becomes exactly like another when you move it in some way: turn, flip or slide. ... There are three basic types of symmetry: rotational symmetry, reflection symmetry, and point symmetry.
The statements that describe a nuclear reaction are may involve a change in total mass, involve very high-energy changes, and involve changes in nuclides when decay takes place.
There are two kinds of nuclear reactions, that is, fission and fusion. Fusion involves the fusion of two light atoms into a heavier atom, while fission involves the splitting of an unstable isotope (with a high mass number) into stable elements of lower mass number, which vary in features from the parent atoms. Both the reactions discharge huge concentration of energies in the process.
Answer:199mL
Explanation:
Let V ml be the volume of blood in animal.
When 1.0 ml sample is added, total volume becomes V+1.0ml. Its activity is 1000 dpm.
After equilibrium, 2.0 ml of the sample had activity of 10 dpm.
Hence, after equilibrium, the activity of V+1.0 ml of blood sample will be 10/2 (V+1.0ml)=1000dpm
Hence, V=199ml.
