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3 years ago

What is the mass number of an atom with 17 protons, 17 electrons, and 20 neutrons?

1 answer:

3 0

The mass number of this particular element is 37

An element with 17 protons will ALWAYS be chlorine.
The mass number is found by adding the element’s protons and neutrons.
protons+neutrons=mass number

Here is the math if needed,
17+20=37

Therefore the mass number is 37

I hope this helped!

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Define what chemical and radiant energy is

juin [17]

Radiant energy is energy contained in electromagnetic waves. These include visible light, infrared, radio waves, ultraviolet and microwaves. ... Chemical energy is energy stored in chemical bonds between atoms.

Photosynthesis is the transformation of radiant energy to chemical energy. Plants take in water, carbon dioxide, and sunlight and turn them into glucose and oxygen. Called photosynthesis, one of the results of this process is that carbon dioxide is removed from the air.

4 0

3 years ago

The Ka for formic acid (HCO2H) is 1.8 × 10-4. What is the pH of a 0.35 M aqueous solution of sodium formate (NaHCO2)?

anzhelika [568]

Answer:

9.36

Explanation:

Sodium formate is the conjugate base of formic acid.

Also,

$K_a\times K_b=K_w$

$K_b$ for sodium formate is $K_b=\frac {K_w}{K_a}$

Given that:

$K_a$ of formic acid = $1.8\times 10^{-4}$

And, $K_w=10^{-14}$

So,

$K_b=\frac {10^{-14}}{1.8\times 10^{-4}}$

$K_b=5.5556\times 10^{-11}$

Concentration = 0.35 M

HCOONa ⇒ Na⁺ + HCOO⁻

Consider the ICE take for the formate ion as:

HCOO⁻ + H₂O ⇄ HCOOH + OH⁻

At t=0 0.35 - -

At t =equilibrium (0.35-x) x x

The expression for dissociation constant of sodium formate is:

$K_{b}=\frac {[OH^-][HCOOH]}{[HCOO^-]}$

$5.5556\times 10^{-11}=\frac {x^2}{0.35-x}$

Solving for x, we get:

x = 0.44×10⁻⁵ M

pOH = -log[OH⁻] = -log(0.44×10⁻⁵) = 4.64

pH + pOH = 14

So,

5 0

3 years ago

In the following reaction, what is the effect on the direction of the reaction if more SO3 is added to the reaction mixture?

Stolb23 [73]

Answer:

The equilibrium shifts to produce more reactants.

Explanation:

According to the Le- Chatelier principle,

At equilibrium state when stress is applied to the system, the system will behave in such a way to nullify the stress.

The equilibrium can be disturb,

By changing the concentration

By changing the volume

By changing the pressure

By changing the temperature

Consider the following chemical reaction.

Chemical reaction:

2SO₂ + O₂ ⇄ 2SO₃

In this reaction the equilibrium is disturb by increasing the concentration of Product.

When the concentration of product is increased the system will proceed in backward direction in order to regain the equilibrium. Because when product concentration is high it means reaction is not on equilibrium state. As the concentration of SO₃ increased the reaction proceed in backward direction to regain the equilibrium state and more reactant is formed.

3 0

3 years ago

HELP ME ON THIS

diamong [38]

Answer:

The attractive force between them decreases

Explanation:

This is because they become localised.

7 0

3 years ago

A sample of gas has a volume of 20.0 mL at STP. What will the volume be if the temperature is changed to 546 K and the pressure

Ostrovityanka [42]

The volume did not change, it remained at 20 ml

<h3>Further explanation</h3>

Given

20 ml a sample gas at STP(273 K, 1 atm)

T₂=546 K

P₂=2 atm

Required

The volume

Solution

Combined gas Law :

$\tt \dfrac{P_1.V_1}{T_1}=\dfrac{P_2.V_2}{T_2}$

Input the value :

$\tt \dfrac{1\times 20}{273}=\dfrac{2\times V_2}{546}\\\\V_2=\dfrac{1\times 20\times 546}{273\times 2}\\\\V_2=20~ml$

The volume does not change because the pressure and temperature are increased by the same ratio as the initial conditions (to 2x)

5 0

3 years ago