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3 years ago

Why does nuclear charge increase as you go left to right across a period

1 answer:

7 0

The atomic number increases moving left to right across a period and subsequently so does the effective nuclear charge. Therefore, moving left to right across a period the nucleus has a greater pull on the outer electrons and the atomic radii decreases.

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Ham radio operators often broadcast on the 6-meter band. The frequency of this electromagnetic radiation is MHz. [speed of light

Volgvan

Answer:

50 MHz

Explanation:

The relation between frequency and wavelength is shown below as:

$c=frequency\times Wavelength$

c is the speed of light having value $3\times 10^8\ m/s$

Given, Wavelength = 6 m

Thus, Frequency is:

$Frequency=\frac{c}{Wavelength}$

$Frequency=\frac{3\times 10^8}{6}\ Hz$

$Frequency=50\times 10^{6}\ Hz$

Also,

Also, 1 Hz = $10^{-6}$ MHz

So, Frequency = 50 MHz.

8 0

3 years ago

0.53g of acetanilide was subjected to kjeldahl determination and the ammonia produced was collected in 50cm3 of 0.50M of h2so4.o

Lady bird [3.3K]

Answer:

10.57% of N in acetanilide

Explanation:

All nitrogen in the sample is converted in NH₃ in the Kjeldahl determination. The NH₃ reacts with H₂SO₄ as follows:

2NH₃ + H₂SO₄ → 2NH₄⁺ + SO₄²⁻

The acid in excess in titrated with Na₂CO₃ as follows:

Na₂CO₃ + H₂SO₄ → Na₂SO₄ + H₂O + CO₂

To solve this question we must find the moles of sodium carbonate = Moles of H₂SO₄ in excess. The added moles - Moles in excess = Moles of sulfuric acid that reacts:

Moles Na₂CO₃ anf Moles H₂SO₄ in excess:

0.025L * (0.05mol / L) = 1.25x10⁻³ moles Na₂CO₃ / 0.01360L =

0.09191M * 0.250L = 0.0230 moles H₂SO₄ in excess.

Moles H₂SO₄ added:

0.050L * (0.50mol / L) = 0.0250 moles H₂SO₄ added

Moles that react:

0.0250 moles - 0.0230 moles = 0.0020 moles H₂SO₄

Moles of NH₃ = Moles N:

0.0020 moles H₂SO₄ * (2mol NH₃ / 1mol H₂SO₄) = 0.0040 moles NH₃ = Moles N

mass N and mass percent:

0.0040 moles N * (14g / mol) = 0.056gN / 0.53g * 100 =

<h3>10.57% of N in acetanilide</h3>

7 0

2 years ago

I went for a walk the other day. I went four blocks east, then seven blocks south, then one block west and finally

nalin [4]

Answer:

a) distance is 4+7+1+8=20 blocks

b) displacement is 10 blocks

Explanation:

find displacement: x and y

x axis displacement = 4-1 = 3 blocks

y axis displacement = -7+8= 1 block

displacement = the square root of 3^2 + 1^2

= 9+1 = 10 blocks.

You can find the angle of displacement with respect to the initial position using trig identities, if you wish.

4 0

2 years ago

Which property of water makes it helpful to use in car radiators?

Nezavi [6.7K]

The correct answer is C) Water takes long to heat and cool down than other liquids.

It doesn't climb up the sides of a tube any more than other solutions do, and being a universal solvent has nothing to do with radiators. It does however take a long time to heat and cool down since you don't have a 100+ celsius burner to heat it up in an instant.

5 0

3 years ago

6. Determine the wavelength for a photon of light

MAVERICK [17]

Answer:

6) λ = 0.84 × 10⁻⁸ m

7) λ = 0.84 × 10⁻⁶ m

Explanation:

6) Given data:

Wavelength of photon = ?

Frequency of photon = 3.56 × 10¹⁶ Hz

Solution:

Formula:

Speed of radiation = frequency × wavelength

c = speed of wave = 3×10⁸ m/s

by putting values,

3×10⁸ m/s = 3.56 × 10¹⁶ Hz × λ

λ = 3×10⁸ m/s / 3.56 × 10¹⁶ s⁻¹

λ = 0.84 × 10⁻⁸ m

7) Given data:

Wavelength of photon = ?

Frequency of photon = 6.15 × 10¹⁴ Hz

Solution:

Formula:

Speed of radiation = frequency × wavelength

c = speed of wave = 3×10⁸ m/s

by putting values,

3×10⁸ m/s = 6.15 × 10¹⁴ Hz × λ

λ = 3×10⁸ m/s / 6.15 × 10¹⁴ Hz s⁻¹

λ = 0.84 × 10⁻⁶ m

6 0

2 years ago