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ki77a [65]
3 years ago
11

18. Focal length is a length which lies between

Chemistry
1 answer:
Jet001 [13]3 years ago
7 0

Answer:

Lens and focal point is the correct answer.

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What is the mass of sodium (Na) in 50 grams of table salt (NaCl)? Show your work.
Margaret [11]

Answer:

19 g

Explanation:

Data Given:

Sodium Chloride (table salt) = 50 g

Amount of sodium (Na) = ?

Solution:

Molecular weight calculation:

NaCl = 23 + 35.5

NaCl = 58.5 g/mol

Mass contributed by Sodium = 23 g

calculate the mole percent composition of sodium (Na) in sodium Chloride.

Since the percentage of compound is 100

So,

Percent of sodium (Na) = 23 / 58.5 x 100

Percent of sodium (Na) = 39.3 %

It means that for ever gram of sodium chloride there is 0.393 g of Na is present.

So,

for the 50 grams of table salt (NaCl) the mass of Na will be

mass of sodium (Na) = 0.393 x 50 g

mass of sodium (Na) = 19 g

8 0
4 years ago
Read 2 more answers
What is the total number of atoms in the molecule
serg [7]

Answer:

Sulfuric acid contains 2 hydrogen atoms, 1 sulfur atom, and 4 oxygen atoms.

Explanation:

8 0
3 years ago
In compliance with conservation of energy, Einstein explained that in the photoelectric effect, the energy of a photon (hv) abso
3241004551 [841]

Answer:

 a) 1.866 × 10 ⁻¹⁹ J      b)   3.685 × 10⁻¹⁹ J

Explanation:

the constants involved are

h ( Planck constant) = 6.626 × 10⁻³⁴ m² kg/s

Me of electron = 9.109 × 10 ⁻³¹ kg

speed of light = 3.0 × 10 ⁸ m/s

a) the Ek ( kinetic energy of the dislodged electron) = 0.5 mu²

Ek = 0.5 × 9.109 × 10⁻³¹ × ( 6.40 × 10⁵ )² = 1.866 × 10 ⁻¹⁹ J

b) Φ ( minimum energy needed to dislodge the electron ) can be calculated by this formula

hv =   Φ + Ek

where Ek = 1.866 × 10 ⁻¹⁹ J

v ( threshold frequency ) = c / λ where c is the speed of light and λ is the wavelength of light = 358.1 nm = 3.581 × 10⁻⁷ m

v = ( 3.0 × 10 ⁸ m/s ) / (3.581 × 10⁻⁷ m ) = 8.378 × 10¹⁴ s⁻¹

hv = 6.626 × 10⁻³⁴ m² kg/s ×  8.378 × 10¹⁴ s⁻¹ = 5.551 × 10⁻¹⁹ J

5.551 × 10⁻¹⁹ J = 1.866 × 10 ⁻¹⁹ J + Φ

Φ = 5.551 × 10⁻¹⁹ J - 1.866 × 10 ⁻¹⁹ J = 3.685 × 10⁻¹⁹ J

7 0
3 years ago
Mendeleev's periodic table of elements was created in 1901.<br> O A. True<br> O B. False
LiRa [457]
B. False
It was created in 1869
3 0
3 years ago
The reason salt crystals, such as kcl, hold together so well is because the cations are strongly attracted to
Lynna [10]
<span>The answer is anions. Cations are positively-charged ions (in this case K+) while anions are negatively-charged ions (in this case Cl-). The ions attract each other  through electrostatic charges and arrange themselves in an ordered fashion to form a lattice</span>




5 0
3 years ago
Read 2 more answers
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