Many extrusive volcanic rocks contain holes which have formed from

Element Q is a theoretical nonmetal with atomic number 59. Consider the isotope: Q-95. How many electrons are in an atom of Q-95

Vinil7 [7]

60

Explanation:

The number of electrons in an atom of Q-95 will be 60 electrons.

The atomic number of an atom is the number of protons in the atom of the isotope

This number is unique to every atom and their isotope

An isotope of an atom is the existence of an atom having the same atomic number but different mass numbers.

Since atomic number the same as number of protons, they are the positively charged particles in an atom.

To have a negative charge, the number of electrons must be more than that of protons.

Charge = number of protons - number electrons

charge = -1

-1 = 59 - number of electrons

Number of electrons = 60 electrons

learn more:

Number of subatomic particles brainly.com/question/2757829

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4 0

2 years ago

50cm3 of 1 mol/dm3 HCl at 30°C was mixed with 50cm3 of 1mol/dm3 NaOH at 30°C in a styrofoam calorimeter. The temperature of the

trapecia [35]

Answer:

-21 kJ·mol⁻¹

Explanation:

Data:

H₃O⁺ + OH⁻ ⟶ 2H₂O

V/mL: 50 50

c/mol·dm⁻³: 1.0 1.0

ΔT = 4.5 °C

C = 4.184 J·°C⁻¹g⁻¹

C_cal = 50 J·°C⁻¹

Calculations:

(a) Moles of acid

$\text{Moles of acid} = \text{0.050 dm}^{3} \times \dfrac{\text{1.0 mol}}{\text{1 dm}^{3}} = \text{0.050 mol}\\\\\text{Moles of base} = \text{0.050 dm}^{3} \times \dfrac{\text{1.0 mol}}{\text{1 dm}^{3}} = \text{0.050 mol}$

So, we have 0.050 mol of reaction

(b) Volume of solution

V = 50 dm³ + 50 dm³ = 100 dm³

(c) Mass of solution

$\text{Mass of solution} = \text{100 dm}^{3} \times \dfrac{\text{1.00 g}}{\text{1 dm}^{3}} = \text{100 g}$

(d) Calorimetry

There are three energy flows in this reaction.

q₁ = heat from reaction

q₂ = heat to warm the water

q₃ = heat to warm the calorimeter

q₁ + q₂ + q₃ = 0

nΔH + mCΔT + C_calΔT = 0

0.050ΔH + 100×4.184×4.5 + 50×4.5 = 0

0.050ΔH + 1883 + 225 = 0

0.050ΔH + 2108 = 0

0.050ΔH = -2108

ΔH = -2108/0.0500

= -42 000 J/mol

= -42 kJ/mol

This is the heat of reaction for the formation of 2 mol of water

The heat of reaction for the formation of mol of water is -21 kJ·mol⁻¹.

5 0

2 years ago

Gelneren [198K]

Answer:

Maybe they both have valence electrons and can be used in chemical reactions. I could be wrong, I don't have any exact answers.

Explanation:

5 0

3 years ago

Find density of nitrogen dioxide at 75*C and 0.805 atm.

Eva8 [605]

Answer:

1 (348) (D2) = 273 (2.05) (0.805) D2= 1.29 g/L

Explanation:

5 0

3 years ago

Which statement best describes a physical change?

yulyashka [42]

The answer is the third one .

7 0

2 years ago