Answer:
sound loudness is measured in decibels, A. True
Mole is equal to mass of the element divided by molar mass of the element. that is
mole=mass/molar mass
From periodic table calcium has a molar mass of 40 g/mol
moles is therefore =800g/40g/mol=20moles
Answer:
- <u><em>Magnesium and fluorine.</em></u>
Explanation:
<em>Ionic compounds</em> are formed by the electrostatic attraction of cations and anions.
Cations, positive ions, are formed when atoms lose electrons, and anions, negative ions, are formed when atoms gain electrons.
When two different atoms have similar atraction for electrons (electronegativity) they will not donate to nor catch electrons from each other, so cations and anions will not be formed. Instead, the atoms would prefer to share electrons forming covalent bonds to complete their outermost shell (octet rule).
Then, in order to form ionic compounds the electronegativities have to substantially different. This situation does not happen between two nonmetal elements, which nitrogen and sulfur are. Then, you can predict safely that nitrogen and sulfur will not form an ionic compound.
Ionic compounds, then require the electronegativity difference that exist between some metals and nonmetals. Being magnesium an alkaline earth metal, its electronegativity is very low. On the other hand, fluorine the first element of the group 17, has the highest electronegativity of all the elements.Thus magnesium and fluorine will have enough electronegativity difference to justify the exchange of electrons, forming ions and, consequently, ionic compounds.
Answer:
c = 0.377 J/g.°C
c = 0.2350 J/g.°C
J = 27.3 J
Explanation:
We can calculate the heat (Q) absorbed or released by a substance using the following expression.
Q = c × m × ΔT
where,
c: specific heat
m: mass
ΔT: change in the temperature
<em>It takes 49.0J to raise the temperature of an 11.5g piece of unknown metal from 13.0°C to 24.3°C. What is the specific heat for the metal? Express your answer numerically, in J/g.°C</em>
Q = c × m × ΔT
49.0 J = c × 11.5 g × (24.3°C - 13.0°C)
c = 0.377 J/g.°C
<em>The molar heat capacity of silver is 25.35 J/mol.°C. How much energy would it take to raise the temperature of 11.5g of silver by 10.1°C? Express your answer numerically, in Joules. What is the specific heat of silver?</em>
<em />
The molar mass of silver is 107.87 g/mol. The specific heat of silver is:
Q = c × m × ΔT
Q = (0.2350 J/g.°C) × 11.5 g × 10.1°C = 27.3 J
