4. Anh measured the temperature of a pond near his house. Before he left for school, the water in the

Otrada [13]

A climograph is a dual-purpose graph, showing two different kinds of information. A bar graph shows how much precipitation a given place receives during a period of time. A line graph shows the temperature conditions for the same place during the same period of time.

8 0

3 years ago

It takes 281.7 kJ of energy to remove 1 mole of electrons from the atoms on the surface of lithium metal. If lithium metal is ir

Alex17521 [72]

Answer:

The maximum kinetic energy of electron is = 2.93 × $10^{-19}$ Joule

Explanation:

We know that total energy

$E = \frac{hc}{\lambda}$ ------------ (1)

Here h = plank's constant = 6.62 × $10^{-34}$ J s

c = speed of light = 3 × $10^{8}$ $\frac{m}{s}$

$\lambda$ = 261 nm = 261 × $10^{-9}$ m

Put all these values in equation (1) we get

E = 7.6 × $10^{-19}$ J

We know that

Total energy = Energy to remove an electron + K.E of electron

Energy to remove an electron = $\frac{281.7 (1000)}{(6.023)10^{23} }$

Energy to remove an electron = 4.67 × $10^{-19}$ J

K.E of electron = Total energy - Energy to remove an electron

K.E of electron = 7.6 × $10^{-19}$ - 4.67 × $10^{-19}$

K.E of electron = 2.93 × $10^{-19}$ Joule

Therefore the maximum kinetic energy of electron is = 2.93 × $10^{-19}$ Joule

3 0

4 years ago

Compound Y has the elements C, H, N and O. It's exact mass is 91.0425. Answer the following questions. Isotope Exact Mass 1H 1.0

Talja [164]

Answer:

Six C atoms (C₆); five H atoms (H₅); one N atom (N); no O atoms

Explanation:

The rule of 13 states that the formula of a compound is a multiple n of 13 (the molar mass of CH) plus a remainder r.

MF = CₙHₙ₊ᵣ

Y has a molecular mass of 91 u

91/13 =7r0

The formula can't be C₇H₇ because a hydrocarbon must have an even number of H atoms,

The odd mass and the odd number of H atoms make it reasonable to add an N atom and subtract CH₂ (CH₂ = 14):

C₇H₇ + N - CH₂ = C₆H₅N

Check:

6C = 6 × 12.000 = 72.000 u

5H = 5 × 1.008 = 5.040

1N = 1 × 14.003 = <u>14.003 </u>

TOTAL = 91.043 u

This is excellent agreement with the observed mass of 91.0425 u.

There are six C atoms (C₆)

There are five H atoms (H₅)

There is one N atom (N)

There are no O atoms.

4 0

3 years ago

H2o has how many atoms in it? 1,2, or 3?

liraira [26]

H2o only has two atoms in it.
(just trying to make this text longer,,,)

4 0

3 years ago

What are the 3 common gases that give off reactions?

Serjik [45]

The 3 common gases that give off reactions are Hydrogen sulfide, Carbon monoxide, Nitrogen oxides.

<h3>What are off reactions</h3>

Off reactions are defined as chemical reactions that occurs when something burns or during combustion of materials which gives off energy.

Some gases that give off reaction are:

Hydrogen sulfide
Carbon monoxide
Nitrogen oxides

Note that these gases are mostly poisonous.

Therefore, the 3 common gases that give off reactions are Hydrogen sulfide, Carbon monoxide, Nitrogen oxides.

Learn more about off reactions here:

brainly.com/question/16416932

#SPJ12

3 0

2 years ago