Answer:
Density = 11.4 g/cm³
Explanation:
Given data:
Density of lead = ?
Height of lead bar = 0.500 cm
Width of lead bar = 1.55 cm
Length of lead bar = 25.00 cm
Mass of lead bar = 220.9 g
Solution:
Density = mass/ volume
Volume of bar = length × width × height
Volume of bar = 25.00 cm × 1.55 cm × 0.500 cm
Volume of bar = 19.4 cm³
Density of bar:
Density = 220.9 g/ 19.4 cm³
Density = 11.4 g/cm³
3.37 x 10¹⁰ molecules
Explanation:
Given parameters:
Volume of water = 1pL = 1 x 10⁻¹²L
Density of water = 1.00g/mL = 1000g/L
Unknown:
Number of water molecules = ?
Solution:
To solve this problem, we first find the mass of the water molecule in the inkjet.
Mass of water = density of water x volume of water
Then, the number of molecules can be determined using the expression below:
number of moles = 
Number of molecules = number of moles x 6.02 x 10²³
Solving:
Mass of water = 1 x 10⁻¹² x 1000 = 1 x 10⁻⁹g
Number of moles:
Molar mass of H₂O = 2 + 16 = 18g/mol
Number of moles =
= 5.6 x 10⁻¹⁴moles
Number of molecules = 5.6 x 10⁻¹⁴ x 6.02 x 10²³ = 33.7 x 10⁹
= 3.37 x 10¹⁰ molecules
Learn more:
Number of molecules brainly.com/question/4597791
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Molarity of solution is mathematically expressed as,
M =

We know that volume = mass/density
Given: mass of solution = 100 g, Density = 1.34 g/ml
∴ volume = 100/1.34 = 88.49 ml = 0.08849 l
Also, we know that molecular weight of sucrose = 342.3 g/mol
∴M =

= 6.979 M
Thus, molarity of solution is 6.979 M
Calcium fluoride.
Ca is metal, F is non-metal, so they form ionic bond.
Ca as metal can form only positive ion. Ca in the second group, so the charge of Ca ion is 2+. Ca²⁺
F is in the 17th group, so it has 7 electrons on the last level. It is non-metal, non-metal, so it has negative charge -(8-7)=-1. "8" because on the last level cannot be more than 8 electrons. F-ion is F¹⁻.
Ca²⁺ F¹⁻
Number of positive charges should be equal to number of negative charges,
Formula of calcium fluoride
CaF2.
2 atoms Fluorine bond with Calcium.
B. nuclear to thermal to mechanical to electrical