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3 years ago

Explain how you figure out the number of neutrons in Tellurium-128.

Chemistry

1 answer:

sweet [91]3 years ago

7 0

Answer:

Explanation:

128 is the mass number. it means protons+nutrons=128

then the atomic number of te-128 is 52. atomic number means the number of protons .

so 128-52=76.

if you don't get it, I'll explain it later

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If an atom has 2 electrons outside of its nucleus, which combination of protons and neutrons would result in a neutral atom?

Dahasolnce [82]

It would be a llllllllllll

8 0

2 years ago

Completion

Snowcat [4.5K]

Answer:

Compress
Fixed
Melts
Melting Point
Freezing Point
High
Crystalline
Lattice
Unit cell
Amorphous solids

Explanation:

Solids tend to be dense and difficult to compress.

They do not flow or take the shape of their containers, like liquids do, because the particles in solids vibrate around fixed points.

When a solid is heated until its particles vibrate so rapidly that they are no longer held in fixed positions, the solid melts.

Melting point is the temperature at which a solid changes to a liquid. The melting and freezing point of a substance are at the same temperature.

In general, ionic solids tend to have relatively high melting points, while molecular solids tend to have relatively low melting points.

Most solids are crystalline

The particles are arranged in a pattern known as a crystal lattice

The smallest subunit of a crystal lattice is the unit cell

Some solids lack an ordered internal structure and are called amorphous solids.

7 0

2 years ago

Calculate the enthalpy change for the thermite reaction: 2al(s)+fe2o3(s)→2fe(s)+al2o3(s), δh∘rxn=−850 kj when 4.00 mol of al und

kolezko [41]

Given:

Enthalpy change ΔH for the thermite reaction = -850 kJ

Moles of Al involved = 4

To determine:

Reaction enthalpy when 4 moles of Al reacts

Explanation:

The thermite reaction is-

2Al(s) + Fe2O3(s) → 2Fe(s) + Al2O3(s)

When 2 moles of Al react the enthalpy change is -850 kJ

therefore, when 4 moles of Al reacts, the change in enthalpy is-

= 4 moles * (-850) kJ/2 moles = -1700 kJ

Ans: Enthalpy change is -1700 kJ

6 0

2 years ago

17.

nataly862011 [7]

Answer:

10 g of powered sugar

Explanation:

The powered sugar will have more surface are for the solvent to dissolve faster

3 0

2 years ago

Ethanol has a Kb of 1.22 Degrees C/m and usually boils at 78.4 Degrees Celcius. How many mol of an nonionizing solute would need

Gala2k [10]

Answer:

0.3097 moles of an nonionizing solute would need to be added.

Explanation:

Molal elevation constant = $k_b=1.22^oC/m$

Normal boiling point of ethanol = $T_o=78.4^oC$

Boiling of solution = $T_b=86.30^oC$

Moles of nonionizing solute = n

Mass of ethanol (solvent) = 47.84 g

Elevation boiling point:

$\Delta T_b=T_b-T_o$

$\Delta T_b=86.30^oC-78.4^oC=7.9^oC$

$\Delta T_b=K_b\times m$

$m=\frac{\text{Moloes of solute}}{\text{Mass of solvent(kg)}}$

$7.9^oC=1.22^oC/m\times \frac{n}{0.04784 kg}$

n = 0.3097 mol

0.3097 moles of an nonionizing solute would need to be added.

4 0

3 years ago