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3 years ago

An atom of calcium contains 20 protons how many electrons does it have

Chemistry

1 answer:

harina [27]3 years ago

4 0

20.

Atomic number is equivalent to its protons and electrons. :)

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How many gallons of gasoline that is 5% ethanol must be added to 2,000 gallons of gasoline with no ethanol to get a mixture that

Amanda [17]

Answer:

$V_1= 3000 gal$

Explanation:

We have 3 solutions:

Solution 1 (with ethanol)
Solution 2 (no ethanol)
Final solution

$V_f=V_1 + V_2$

and for the ethanol:

$V_f*0.03=V_1*0.05 + V_2*0$

$V_f=V_1 \frac{5}{3}$

Combining:

$V_1 \frac{5}{3}=V_1 + V_2$

$V_1 \frac{2}{3}= V_2$

$V_1= \frac{3}{2} V_2$

If V2=2000 gal:

$V_1= \frac{3}{2} 2000 gal$

$V_1= 3000 gal$

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3 years ago

Explain why the electron configuration of 2-3-1 represents an atom in an excited state.

Allushta [10]

Answer:

The excited state electron configuration of an atom indicates the promotion of a valence electron to a higher energy state.

4 0

2 years ago

Which element has the same number of energy levels as aluminum (Al) and the same number of valence electrons as calcium (Ca)

GREYUIT [131]

Answer:

magnesium (Mg)

Explanation:

8 0

2 years ago

Read 2 more answers

Name 3 sources of carbohydrates for the production of an alcoholic drink

icang [17]

Answer:An alcoholic drink is a drink that contains ethanol, a type of alcohol produced by fermentation of grains, fruits, or other sources of sugar. The consumption of alcohol plays an important social role in many cultures. Most countries have laws regulating the production, sale, and consumption of alcoholic beverages.

Explanation: vodka the preferred alcoholic beverage of choice among alcoholics? #3 Doesn't make you feel bloated or full like beer does. It goes down quickly and smooth. #4 Gets you drunk just as fast as any other hard liquor can, and obviously much faster than beer or wine.

4 0

2 years ago

Burka [1]

Answer:

$\large \boxed{\text{E) 721 K; B) 86.7 g}}$

Explanation:

Question 7.

We can use the Combined Gas Laws to solve this question.

a) Data

p₁ = 1.88 atm; p₂ = 2.50 atm

V₁ = 285 mL; V₂ = 435 mL

T₁ = 355 K; T₂ = ?

b) Calculation

$\begin{array}{rcl}\dfrac{p_{1}V_{1}}{T_{1}}& =&\dfrac{p_{2}V_{2}}{T_{2}}\\\\\dfrac{1.88\times285}{355} &= &\dfrac{2.50\times 435}{T_{2}}\\\\1.509& = &\dfrac{1088}{T_{2}}\\\\1.509T_{2} & = & 1088\\T_{2} & = & \dfrac{1088}{1.509}\\\\ & = & \textbf{721K}\\\end{array}\\\text{The gas must be heated to $\large \boxed{\textbf{721 K}}$}$

Question 8. I

We can use the Ideal Gas Law to solve this question.

pV = nRT

n = m/M

pV = (m/M)RT = mRT/M

a) Data:

p = 4.58 atm

V = 13.0 L

R = 0.082 06 L·atm·K⁻¹mol⁻¹

T = 385 K

M = 46.01 g/mol

(b) Calculation

$\begin{array}{rcl}pV & = & \dfrac{mRT}{M}\\\\4.58 \times 13.0 & = & \dfrac{m\times 0.08206\times 385}{46.01}\\\\59.54 & = & 0.6867m\\m & = & \dfrac{59.54}{0.6867 }\\\\ & = & \textbf{86.7 g}\\\end{array}\\\text{The mass of NO$_{2}$ is $\large \boxed{\textbf{86.7 g}}$}$

7 0

3 years ago