Answer:
iron (Fe)
Explanation:
Use q = mcΔT.
q = 1.396 x 10^2 J
m = 15.5g
ΔT = (45.0 - 25.0) = 20 degrees celcius
1.396 x 10^2 = 15.5 x c x 20
c = .450 J/g x degrees celcius
This is closest to the specific heat of iron/steel.
Sodium hydrogen carbonate has:

The + from Na+ and + from H+ makes 2+, and therefore the 2- from CO3 evens the charges to neutral.
Not to be confused with Sodium Carbonate, (Na2CO3), which lack an H, Sodium Hydrogen Carbonate is sometimes shortened to just Sodium Bicarbonate. It is used in the kitchen (cooking) as "baking soda."
Formula: NaHCO3
<u>Answer:</u> The final volume will be 16.85 mL
<u>Explanation:</u>
To calculate the new pressure, we use the equation given by Boyle's law. This law states that pressure is inversely proportional to the volume of the gas at constant temperature.
The equation given by this law is:

where,
are initial pressure and volume.
are final pressure and volume.
We are given:
Conversion factor: 1 atm = 760 torr

Putting values in above equation, we get:

Hence, the final volume will be 16.85 mL
Explanation:
chemical to add to swimming pools in order
to make the water safer. She mixed two solid
substances together in a sealed container.
The diagram above shows the repeating
groups of atoms that make up the two
starting substances.
After mixing, Tiana found two liquid
substances in the sealed container.
(Nothing had escaped.) Which of the
diagrams to the left shows the repeating
groups of atoms that make up the ending
substances?
Answer:
The given atom is of Ca.
Explanation:
Given data:
Speed of atom = 1% of speed of light
De-broglie wavelength = 3.31×10⁻³ pm (3.31×10⁻³ / 10¹² = 3.31×10⁻¹⁵ m)
What is element = ?
Solution:
Formula:
m = h/λv
m = mass of particle
h = planks constant
v = speed of particle
λ = wavelength
Now we will put the values in formula.
m = h/λv
m = 6.63×10⁻³⁴kg. m².s⁻¹/3.31×10⁻¹⁵ m ×( 1/100)×3×10⁸ m/s
m = 6.63×10⁻³⁴kg. m².s⁻¹/ 0.099×10⁻⁷m²/s
m = 66.97×10⁻²⁷ Kg/atom
or
6.69×10⁻²⁶ Kg/atom
Now here we will use the Avogadro number.
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
For example,
18 g of water = 1 mole = 6.022 × 10²³ molecules of water
Now in given problem,
6.69×10⁻²⁶ Kg/atom × 6.022 × 10²³ atoms/ mol × 1000 g/ 1kg
40.3×10⁻³×10³g/mol
40.3 g/mol
So the given atom is of Ca.