Which statement describes how chemical formulas like h2o represent compounds

Which of the following has no electrons? Use a periodic table. Question 1 options: H He H– He 2+ Save

Elodia [21]

An electron is a negatively charged subatomic particle present in the space outside the nucleus of an atom. The loss of electron from an atom results in the formation of cation whereas gaining of electron by an atom results in the formation of anion. The cation possesses positive charge due to loss of electron and anion possesses negative charge due to gain of electron.

The neutral atom has no charge on it.

For given atomic symbols:

$H$

The atomic number of hydrogen is 1 and the given symbol has no charge that means it is in its neutral state. So, the number of electrons in $H$ is 1.

$He$

The atomic number of helium is 2 and the given symbol has no charge that means it is in its neutral state. So, the number of electrons in $He$ is 2.

$H^{-}$

The atomic number of hydrogen is 1 and the given symbol has a negative charge that represents a gain of electron. So, the number of electrons in $H^{-}$ is 2.

$He^{2+}$

The atomic number of helium is 2 and the given symbol has two positive charge that represents loss of two electrons. So, the number of electrons in $He^{2+}$ is 0.

Hence, $He^{2+}$ has no electrons.

6 0

4 years ago

IF the strong nuclear force affects all particles that are close to each other, What will happen if we add two neutrons to our n

Alina [70]

Answer: it will increase the strong nuclear force in the nucleus

Explanation: Labster

7 0

4 years ago

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Atoms of the LEAST reactive elements tend to have A. one or seven valence electrons. B. eight valence electrons. C. four or five

Tomtit [17]

B. eight valence electrons.

3 0

3 years ago

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What are the potential problems for nearby water sources when using nuclear energy? Check all that apply.

Usimov [2.4K]

The energy discharged at the time of nuclear fusion or fission, mainly when used to produce electricity is known as nuclear energy. Although nuclear energy has become one of the most potent sources of energy in the present time, it also brings some harmful effects along with it, mainly by affecting the surrounding environment like the water bodies present nearby.

Some of the potential problems for the nearby water sources when using nuclear energy are:

1. It contaminates water with radioactive waste.

2. It creates hazardous conditions for the species living in the water.

3. It adds very hot water to cool water environments.

4. It utilizes a resource, which becomes scarce at the time of drought.

5 0

3 years ago

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(1.) Using Beer's Law, How will the absorbance measured for the solutions change as the concentration of aspirin in solutions in

Vesnalui [34]

Answer:

(1) The absorbance of the aspirin in solutions will increase.

(2) [ASA]f = 3.79x10⁻⁴M

(3) [ASA]i = 3.79x10⁻³M

(4) m ASA = 0.171g

Explanation:

The Beer's Law is expressed by:

$A = \epsilon \cdot l \cdot C$ (1)

where A: is the absorbance of the species, ε: is the molar attenuation coefficient, l: is the pathlength and C: is the concentration of the species

(1) From equation (1), the relation between the absorbance of the species and its concentration is directly proportional, so if the aspirin concentration in solutions increases, the absorbance of the solutions will also increase.

(2) Starting in the given expression for the relationship between absorbance and concentration of ASA, we can calculate its concentration in the solution:

$A = 1061.5 \cdot [ASA]$

$[ASA] = \frac{A}{1061.5} = 3.79 \cdot 10^{-4}M$

Therefore, the aspirin concentration in the solution is 3.79x10⁻⁴ M

(3) To calculate the stock solution concentration, we can use the next equation:

$V_{i} [ASA]_{i} = V_{f} [ASA]_{f}$

where Vi: is the stock solution volume=10mL, Vf: is the solution diluted volume=100mL, [ASA]i: is the aspirin concentration of the stock solution and [ASA]f: is the aspirin concentration of the diluted solution

$[ASA]_{i} = \frac{V_{f} \cdot [ASA]_{f}}{V_{i}} = \frac {100mL \cdot 3.79\cdot 10^{-4} M}{10mL} = 3.79 \cdot 10^{-3} M$

Hence, the concentration of the stock solution is 3.79x10⁻³M

(4) To determine the aspirin mass in the tablet, we need to use the following equation:

$m_{ASA} = \eta_{ASA} \cdot M_{ASA} = [ASA]_{i} \cdot V_{0} \cdot M_{ASA}$

where η: is the aspirin moles = [ASA]i V₀, M: is the molar mass of aspirin=180.158g/mol, V₀: is the volume of the volumetric flask=250mL and [ASA]i: is the aspirin concentration in the volumetric flask which is equal to the stock solution=3.79x10⁻³M

$m_{ASA} = 3.79 \cdot 10^{-3} \frac{mol}{L} \cdot 0.250L \cdot 180.158 \frac{g}{mol} = 0.171 g$

Then, the aspirin mass in the tablet is 0.171 g.

I hope it helps you!

5 0

3 years ago