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3 years ago

BRAINLIESTT ASAP! PLEASE HELP :)

Chemistry

1 answer:

nexus9112 [7]3 years ago

6 0

Explanation:

First two pictures go together

From top to bottom, ionisation energy decreases [electron shielding], while from left to right, ionisation energy increases [valence shell stability]. Noble gases always always possess such high energy of ionisation because they are stable, with Helium having the highest ionisation of all elements.

From top to bottom, electron affinity decreases [decrease in atomic radius], while from left to right, electron affinity increases [increase in atomic radius].

There are many more trends, but I have ran out of space, so I will put this in the comments.

I am joyous to assist you anytime.

You might be interested in

Why does pressure vary in the atmosphere

Digiron [165]

Pressure varies in the atmosphere because air molecules are being pulled down towards the center of the earth-hope this helps!

7 0

3 years ago

Boron has primarily two isotopes, one with an atomic mass of 11.0 amu and another with an atomic mass of 10.0 amu. If the abunda

Masja [62]

Answer:

The atomic mass of the boron atom would be 10.135

Explanation:

This is generally known as relative atomic mass.

Relative atomic mass or atomic weight is a physical quantity defined as the ratio of the average mass of atoms of a chemical element in a given sample to the atomic mass of 1/12 of the mass of a carbon-12 atom. Since both quantities in the ratio are masses, the resulting value is dimensionless; hence the value is said to be relative and does not have a unit.

Note that the relative atomic mass of atoms is not always a whole number because of it being isotopic in nature.

Divide each abundance by 100 then multiply by atomic mass
Do that for each isotope, then add the two result. Thus

Relative atomic mass of Boron = (18.5/100 x 11) + (81/100 x 10)

= 2.035 + 8.1

= 10.135

5 0

2 years ago

How much heat is needed warm 65.34 g of water from 18.43 to 21.75

BaLLatris [955]

Given that

Mass of water = 65.34 g

Amount of heat = mass of water * specific heat (temperature change

)

= 65.34 g * 4.184 J / g-C ( 21.75-18.43 )C

= 907.63 J

= 0.908 KJ

And

1 cal = 4.186798 J

907.63 J * 1 cal / 4.186798 J =216.78 cal

Or0.218 kcal

5 0

3 years ago

Can anybody check my answer?

anzhelika [568]

Answer:

$\boxed{\text{25. 20 L; 26. 49 K}}$

Explanation:

25. Boyle's Law

The temperature and amount of gas are constant, so we can use Boyle’s Law.

$p_{1}V_{1} = p_{2}V_{2}$

Data:

$\begin{array}{rcrrcl}p_{1}& =& \text{100 kPa}\qquad & V_{1} &= & \text{10.00 L} \\p_{2}& =& \text{50 kPa}\qquad & V_{2} &= & ?\\\end{array}$

Calculations:

$\begin{array}{rcl}100 \times 10.00 & =& 50V_{2}\\1000 & = & 50V_{2}\\V_{2} & = &\textbf{20 L}\\\end{array}\\\text{The new volume will be } \boxed{\textbf{20 L}}$

26. Ideal Gas Law

We have p, V and n, so we can use the Ideal Gas Law to calculate the volume.

pV = nRT

Data:

p = 101.3 kPa

V = 20 L

n = 5 mol

R = 8.314 kPa·L·K⁻¹mol⁻¹

Calculation:

101.3 × 20 = 5 × 8.314 × T

2026 = 41.57T

$T = \dfrac{2026}{41.57} = \textbf{49 K}\\\\\text{The Kelvin temperature is }\boxed{\textbf{49 K}}$

6 0

3 years ago

A 6.50x10^-5 m solution of potassium permanganate has a percent transmittance of 27.3% when measured in a 1.15 cm cell at a wave

mihalych1998 [28]

For this problem, we use the Beer Lambert's Law. Its usual equation is:

A = ∈LC
where
A is the absorbance
∈ is the molar absorptivity
L is the path length
C is the concentration of the sample solution

As you notice, we only have to find the absorbance. But since we are not given with the molar absorptivity, we will have to use the modified equation that relates % transmittance to absorbance:

A = 2 - log(%T)
A = 2 - log(27.3)
A = 0.5638

7 0

2 years ago