1. it’s use for our food in like microwaves and ovens
2. airplanes are guided by radar waves,
3.the tv is used by electromagnetic waves
4. they are used in heaters,
5.infrared cameras which detect people in the dark
6.Allows airport security to observe the internal contents of objects and luggage using airport scanners
7.doctors use electromagnetic waves in x-rays
Answer:
Explanation:
The melting point of a substance is the temperature at which its melt. The state of a substance is dependent on it's melting temperature. Generally, melting point above 25 °C is a solid.
This means phenol is a solid
Duodecane has melting point below 25 °C hence it is either a liquid or gas. However its boiling point of 216 °C means it would require higher temperature to boil it. Since 25 °C is less than 216 °C it means that it would remain in the liquid state.
Methane has melting point below 25 °C hence it is either a liquid or gas. However its boiling point of -164 °C means it boils easily even at very low temperatures. Since 25 °C is greater than -164 °C it means that it would exist in the gaseous state
Answer:
1. Ionic bonding
2. Covalent bonding
3. Metallic bonding
Explanation:
Ionic bonding also referred to as electrovalent bonding is a kind of chemical bonding that involves the transfer of electrons between the valence shells of two elements with a large electronegativity difference usually a metal and a nonmetal.
For example an ionic bonding scenario might play out between a group one metal and a group seven halogen. While group one metals have one electron hindering their stability, group seven halogens need that one electron that could make them achieve this stability. It is this that causes them to come together in a way where the electron is transferred completely from the valence shell of the group 1 atom and accepted into the valence shell of the group 7 halogen.
Covalent bonding involves the sharing of electrons between atoms of comparable electronegativities. The electro negativity difference is not large enough to permit the total movement of the electrons and hence the electrons are then controlled by the nuclei of the two atoms
Between two metals, what we have is called the metallic bonding
Answer:
option D is correct
Explanation:
no of moles in 3 grams of HCL=3/36=0.08
if 1 mole of HCL require 1 mole of NaOH then 0.08 moles required 0.08 moles of NaOH
mass of 0.08 moles of NaOH=moles*molar mass=0.08*40=3.2 grams
so 3 grams are required in the reaction
Answer:
Final temperature = 
Explanation:
Given that,
Heat added, Q = 250 J
Mass, m = 30 g
Initial temperature, T₁ = 22°C
The Specific heat of Cu= 0.387 J/g °C
We know that, heat added due to the change in temperature is given by :
Put all the values,
So, the final temperature is equal to .
