An atom contains 31 protons,39neutrons and 31 electrons.Identify the mass number of this atom

Recording station x has determined that the epicenter of a recent earthquake was 250 km away. no information is available yet fr

KatRina [158]

The epicenter was located somewhere on a circle centered at Recording station X, with a radius of 250 km.

7 0

3 years ago

Read 2 more answers

d perovskite single crystals with suppressed ion migration for high-performance planar-type photodetectors, small

Naily [24]

Due to their improved charge transfer and great environmental stability, 2D Dion-Jacobson (DJ) perovskites have recently received a lot of attention.

Unfortunately, due to the scarcity of high-quality single crystals for precise measurements, their fundamental optoelectronic capabilities are mainly unknown. Here, a reactive, low-temperature-gradient crystallization method is created using 1,4-butanediammonium as a short-chain insulating spacer to generate high-quality 2D perovskite single crystal (BDAPbI4). It is discovered that the BDAPbI4 single crystal exhibits a direct bandgap with effective charge collection (μτ = 1.45 × 10−3 cm2 V−1). The BDAPbI4 single crystal in particular exhibits the expected high ion migration activation energy (0.88 eV).

Learn more about charge transfer here-

brainly.com/question/20342415

#SPJ4

3 0

2 years ago

an unknown molecule is found to consist of 24.2% carbon by mass, 4.0% hydrogen by mass and the remaining mass is due to chlorine

Paha777 [63]

Answer:

C3 H6 Cl 3

Explanation:

C -24.2%

H - 4.0%

Cl - (100-24.2 - 4.0)=73.8 %

We can take 100g of the substance, then we have

C -24.2 g

H - 4.0 g

Cl - 73.8 g

Find the moles of these elements

C -24.2 g/12.0 g/mol =2.0 mol

H - 4.0 g/1.0 g/mol = 4. 0 mol

Cl - 73.8 g/ 35.5 g/mol = 2.1 mol

Ratio of these elements gives simplest formula of the substance

C : H : Cl = 2 : 4 : 2 = 1 : 2 : 1

CH2Cl

Molar mass (CH2Cl) = 1*12.0 +2*1.0 + 1*35.5 = 49.5 g/mol

Real molar mass = 150 g/mol

real molar mass/ Molar mass (CH2Cl) = 150 /49.5=3

So, Real formula should be C3 H6 Cl 3.

4 0

4 years ago

Read 2 more answers

All of the following reactions can be described as displacement reactions except:____________.

Lady_Fox [76]

Answer:

b

Explanation:

The reaction that is not a displacement reaction from all the options is $C_6H_6_{(l)} + Cl_{2(g)} --> C_6H_5Cl_{(l)} + HCl_{(g)}$

In a displacement reaction, a part of one of the reactants is replaced by another reactant. In single displacement reactions, one of the reactants completely displaces and replaces part of another reactant. In double displacement reaction, cations and anions in the reactants switch partners to form products.

Options a, c, d, and e involves the displacement of a part of one of the reactants by another reactant while option b does not.

Correct option = b.

8 0

3 years ago

PLSSSSS HELP I DONT GET THIS PROBLEMMMM

Aleks [24]

Answer:

C. 7370 joules.

Explanation:

There is a mistake in the statement. Correct form is described below:

Using the above data table and graph, calculate the total energy in Joules required to raise the temperature of 15 grams of ice at -5.00 °C to water at 35 °C.

The total energy needed to raise the temperature is the combination of latent and sensible heats, all measured in joules, and represented by the following model:

$Q = m\cdot [c_{i} \cdot (T_{2}-T_{1})+L_{f} + c_{w}\cdot (T_{3}-T_{2})]$ (1)

Where:

$m$ - Mass of the sample, in grams.

$c_{i}$ - Specific heat of ice, in joules per gram-degree Celsius.

$c_{w}$ - Specific heat of water, in joules per gram-degree Celsius.

$L_{f}$ - Latent heat of fusion, in joules per gram.

$T_{1}$ - Initial temperature of the sample, in degrees Celsius.

$T_{2}$ - Melting point of water, in degrees Celsius.

$T_{3}$ - Final temperature of water, in degrees Celsius.

$Q$ - Total energy, in joules.

If we know that $m = 15\,g$ , $c_{i} = 2.06\,\frac{J}{g\cdot ^{\circ}C}$ , $c_{w} = 4.184\,\frac{J}{g\cdot ^{\circ}C}$ , $L_{f} = 334.72\,\frac{J}{g}$ , $T_{1} = -5\,^{\circ}C$ , $T_{2} = 0\,^{\circ}C$ and $T_{3} = 35\,^{\circ}C$ , then the final energy to raise the temperature of the sample is:

$Q = (15\,g)\cdot \left[\left(2.06\,\frac{J}{g\cdot ^{\circ}C} \right)\cdot (5\,^{\circ}C)+ 334.72\,\frac{J}{g} + \left(4.184\,\frac{J}{g\cdot ^{\circ}C}\right)\cdot (35\,^{\circ}C) \right]$

$Q = 7371.9\,J$

Hence, the correct answer is C.

8 0

3 years ago

An atom contains 31 protons,39neutrons and 31 electrons.Identify the mass number of this atom​

An atom contains 31 protons,39neutrons and 31 electrons.Identify the mass number of this atom