Answer:
A. Because they are compounds, they cannot be pure substances.
Explanation:
The false statement from the given choices is that because they are compounds they cannot be pure substances. In fact, because they are compounds they are pure substances.
Pure substances are made up of elements and compounds and they have the following properties:
- All parts are the same throughout
- Composition is definite
- They cannot easily be separated or broken
- Separation by physical method is not easy
- They have unique sets of physical and chemical properties.
It respresents the higher energy level than 627nm .
<h3>What is a emission line ? </h3>
Emission lines are the glowing hot gas emits lines of light whereas absorption line refers to the tendency of cool atmospheric gas to absorb the same line of light.Some lights produce dark band when the light passes through gas in the atmosphere . There are two line spectrum and absorption.
spectrum is an excitement of electrons from lower to higher energy levels and when it comes back it releases energy in the terms of colourful lights .
It represents the higher energy levels than 627nm because Energy is inversly proportional to wavelength .
to learn more about Emission lines click here
brainly.com/question/28184999
#SPJ9
Answer:
43 mole
Explanation:
Given data:
Number of atoms of Li = 2.6× 10²⁵ atoms
Number of moles = ?
Solution:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance. The number 6.022 × 10²³ is called Avogadro number.
1 mole = 6.022 × 10²³ atoms
2.6× 10²⁵ atoms × 1 mole / 6.022 × 10²³ atoms
0.43 × 10² mole
43 mole
It is energy associated with gravity or gravitational force. (Potential<span> </span>energy<span> held by an object because of its high position compared to a lower position).</span>
Mass:20g
Mole=20/[2(23)+16]
=0.32 mil