Answer: See below
Explanation: a. The mass of an element is composed of:
protons: 1 amu each
neutrons: 1 amu each
electrons: 0 amu each
Only the protons and neutrons are counted in the atomic mass of an element
b. Electrons are assigned a mass of 0. They do have a mass, but it is exceedingly small compared to the protons and neutrons, so they are left out of the calculation of an element's mass.
c. An element becomes unstable if the neutrons exceed the protons by a certain ratio, dependent on the element.
Answer:
1,2,3
Explanation:
Heat gain implies that heat is absorbed by the system in order to make the stated phase transition possible.
Before a liquid changes to gas, intermolecular forces in the liquid are broken by energy supplied as heat.
Also, transition from solid to liquid requires energy to break intermolecular bonds.
Finally, sublimation requires input of energy in the form of heat.
Answer:
V = m
d = 14 830 g × 1
c
m
³
19.32
g = 767.6 cm³
Answer:
Mass = 73.73 g
Explanation:
Given data:
Mass of Mg used = 24.48 g
Mass of HCl used = ?
Mass of hydrogen gas produced = 2.04 g
Mass of Magnesium chloride produced = 96.90 g
Solution:
Chemical equation:
Mg + 2HCl → MgCl₂ + H₂
Number of moles of Mg:
Number of moles = mass/ molar mass
Number of moles = 24.48 g/ 24.305 g/mol
Number of moles = 1.01 mol
Now we will compare the moles of Mg with HCl from balance chemical equation.
Mg : HCl
1 ; 2
1.01 : 2/1× 1.01 = 2.02 mol
Mass of HCl react:
Mass = number of moles × molar mass
Mass = 2.02 × 36.5 g/mol
Mass = 73.73 g
