A.
Weldings sparks could start fire on wood.
Lightning can ignite a fire one a tall tree
Open flames can start another fire if made in contact especially with flammable substances
False They can function as both. An example is Aluminium Oxide. These kind of substances are called "Amphoteric", they can behave as both acids and bases.
Answer: Option (b) is the correct answer.
Explanation:
A chemical reaction in which heat energy is absorbed by the reactant molecules is known as an endothermic reaction.
Therefore, upon completion of this reaction the container in which reaction is carried out becomes colder.
A chemical reaction in which heat energy is released by the reactant molecules is known as an exothermic reaction.
Therefore, upon completion or during this type of reaction the container in which reaction is carried out becomes hot.
Thus, we can conclude that when the test tube gets colder as the reaction takes place then it means this chemical reaction is endothermic reaction.
Answer:
the property that is shared between liquids us called thermometric property your welcome

(i) 1 mole of Ar =6.022×10^23
atoms of Ar
52 mol of Ar=52×6.022×10 ^23
atoms of Ar =3.131×10 ^25 atoms of Ar
(ii) Atomic mass of He = 4amu
Or
4amu is the mass of He atoms = 1
Therefore 52 amu is the mass of He atoms=0.25×52=13 atoms of He
(iii) Gram atomic mass of He = 4g
Or
4g of He contains =6.022×10 ^23
atoms
Therefore 52 g of He contains=
6.022×10 ^23/4×52 =7.83×10 ^24 atoms