Answer:
element
Explanation:
elements consist of pure substances
Explanation:
Calcium is the element that has 2 valence electrons.
Answer:
An atom is a particle of matter that uniquely defines achemical element. An atom consists of a central nucleus that is usually surrounded by one or more electrons. ... The nucleus is positively charged, and contains one or more relatively heavy particles known as protons and neutrons. A proton is positively charged.
Answer:
P₂ = 1312.88 atm
Explanation:
Given data:
Initial temperature = 25°C
Initial pressure = 1250 atm
Final temperature = 40°C
Final pressure = ?
Solution:
Initial temperature = 25°C (25+273.15 = 298.15 K)
Final temperature = 40°C ( 40+273.15 = 313.15 k)
The pressure of given amount of a gas is directly proportional to its temperature at constant volume and number of moles.
Mathematical relationship:
P₁/T₁ = P₂/T₂
Now we will put the values in formula:
1250 atm / 298.15 K = P₂/313.15 K
P₂ = 1250 atm × 313.15 K / 298.15 K
P₂ = 391437.5 atm. K /298.15 K
P₂ = 1312.88 atm
Answer : The energy required to melt 58.3 g of solid n-butane is, 4.66 kJ
Explanation :
First we have to calculate the moles of n-butane.

Given:
Molar mass of n-butane = 58.12 g/mole
Mass of n-butane = 58.3 g
Now put all the given values in the above expression, we get:

Now we have to calculate the energy required.

where,
Q = energy required
= enthalpy of fusion of solid n-butane = 4.66 kJ/mol
n = moles = 1.00 mol
Now put all the given values in the above expression, we get:

Thus, the energy required to melt 58.3 g of solid n-butane is, 4.66 kJ