<span>A substance is composed entirely of one type of atom, it is known as a Chemical element
because mixture contain more than one type of atom and it cannot be neutron or isotope
so correct option is B
hope it helps</span>
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The mass of solid lead would displace exactly 234.6 liters of water should be <span>2,674,440</span>
<span>The Law of Conservation of Mass simply states
that the total amount of mass should not change in a chemical reaction that is
isolated (no other objects can enter the reaction). The total mass of the
reactants must be equal to the total mass of the products. Thus, t</span>he correct estimate of
the amount of oxygen used in the interaction is the difference between 133
g and 29 g.
Answer:
A is the correct answer.
Explanation:
An atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.
All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example if neutral atom has 6 protons than it must have 6 electrons. The sum of neutrons and protons is the mass number of an atom while the number of protons are number of electrons is the atomic number of an atom.
For example in case of Helium:
The 1st one diagram shows that arrow is pointing with in nucleus. The helium nucleus contain two protons and two neutrons. Thus maximum mass is present with in nucleus. while two electrons are revolve around the nucleus and mass of electron is negligible.
Answer:
The solution is given below
Explanation:
Heat, q= mc∆T
q= 125g x 4.18 J/g∙°C x (21.18x- 24.28) °C
q= -1619.75J
NEGATIVE SIGN INDICATES THAT HEAT IS ABSORBED.
Enthalpy Change, ∆H = 1619.75 7/ 10.5 g
= 154.26 J/g
No. of moles of KBr = Mass of KBr/ Molecular Weight of KBr
=10.5g/119gmol-1
=0.088 mol
∆H= 1619.75 J/ 0.088 mol
= 18.41 kJ/mol
