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3 years ago

For the following nuclear reaction, what was the beginning radionuclide (X)? X → 86Rn222 + 2He4

1 answer:

3 0

The original radioisotope underwent double-alpha decay, where the original nucleus lost a total of 4 protons and 4 neutrons.

The original radioisotope would have an atomic number of 86+4 (protons), and would have an atomic mass of 222+8 (protons + neutrons). This would make the element Thorium-230, or 90Th230.

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A strong acid, HA, is added to water. Which statement about the solution is true?

Arturiano [62]

My answer to this question is C

3 0

3 years ago

Convert 1000mg=__g 1L=__mL 160cm=__mm 1.4km=__m 109g=__kg 250m=__km 80cm=__m 75mL=__L 5.6m=__cm 6.5g=__mg 170.4m=__cm 564Dg=__g

Snowcat [4.5K]

Answer:

1000mg= 1g

1L= 1000 mL

160cm = 1600mm

1.4km= 1400m

109 g = 0.109kg

250m= 0.250 km

80cm= 0.8 m

75mL= 0.075L

5.6m= 560 cm

6.5g= 6500mg

170.4m= 17040 cm

564 Dg = 5640 g

58 dg = 5800 mg

600 L= 0.6 KL

0.0923Km= 92300 mm

Explanation:

1 mg = 1x10⁻³ g

1 g = 1000 mg

1 g = 10 dg

1 g = 1x10⁻³ kg

1 Dg = 10 g

1 dg = 100 mg

1 L = 1000 mL

1 L = 1x10⁻³ KL

1 mL = 1x10⁻³ L

1 km = 1000 m

1 km = 1x10⁶ mm

1 m = 1x10⁻³ km

1 cm = 1x10⁻² m

1 cm = 10 mm

5 0

3 years ago

Why do the densities of most substances increase when temperature decreases?

vlada-n [284]

This is because temperatures determine the kinetic energy of molecules of a substance, At lower temperatures the molecules have low kinetic energy hence the distance between molecules is not as large as when the kinetic energy is higher (because the molecules bombard less and with less kinetic energy). This means the substance can pack more molecules per volume at lower temperatures. The more the molecules per volume the higher the density.

6 0

3 years ago

Read 2 more answers

Write balanced chemical equation for the reactions used to prepare each of the following compounds from the given starting mater

creativ13 [48]

Explanation:

A balanced chemical equation is defined as the one that contains same number of atoms on both reactant and product side.

Whereas a chemical reaction that brings change in oxidation state of the reacting species is known as a redox reaction.

When there occurs decrease in oxidation number of an element then it shows the element has been reduced. And, if there occurs an increase in oxidation state of an element then it means the element has been oxidized.

(a) The reaction between nitrogen and hydrogen to form ammonia will be as follows.

$N_{2} + 3H_{2} \rightarrow 2NH_{3}$

So here, oxidation state of nitrogen is changing from 0 to -3. Whereas oxidation state of hydrogen is changing from 0 to +3.

Reaction between ammonia and nitric acid will be as follows.

$NH_{3} + HNO_{3} \rightarrow NH_{4}NO_{3}$

Since, it is a combination reaction. Therefore, no change in oxidation state of reacting species is taking place.

(b) Reaction for conversion of liquid bromine to hydrogen bromide is as follows.

$H_{2}(g) + Br_{2}(l) \rightarrow 2HBr(g)$

Here, oxidation state of hydrogen is changing from 0 to +1. Therefore, oxidation of hydrogen is taking place. On the other hand, oxidation state of bromine is changing from zero to -1. Therefore, reduction of bromine is taking place.

(c) Reaction between Zn and S will be as follows.

$Zn(s) + S(s) \rightarrow ZnS(s)$

Here, oxidation state of zinc is changing from 0 to +2. Hence, oxidation of zinc is taking place.

Oxidation state of sulfur is changing from 0 to -2. Therefore, reduction of sulfur is taking place.

7 0

3 years ago

To what final concentration of NH3 must a solution be adjusted to just dissolve 0.060 mol of NiC2O4 (Ksp = 4×10−10) in 1.0 L of

ololo11 [35]

Given:
0.060 mol of NiC2O4
Ksp = 4 x 10⁻¹⁰
1.0 L of solution
Kf of Ni(NH3)6 2⁺ = 1.2 x 10⁹
NiC2O4 + 6NH3 ⇋ Ni(NH3)6 2+ + 2O4 2- 
NiC2O4 ⇋ Ni 2+ + C2O4 2- ...Ksp 
Ni2+ + 6NH3 ⇋ Ni(NH3)6 2+...Kf 

Ksp * Kf = (4 x 10⁻¹⁰) * (1.2 x 10⁹) = 0.48

K = 0.48 = [Ni(NH3)6 2+][C2O4 2-] / [NH3]⁶
0.48 = (0.060)² / [NH3]⁶ ... (dissolved C2O4 2- = 0.060M)
[NH3]⁶ = (0.060)² / 0.48 = 0.0036 / 0.48 = 0.0075
NH3 = ⁶√0.0075

NH3 = 0.44 M

3 0

3 years ago