Answer: I dunno that but u should give me brainliest
Explanation:
The definition of a gem is "a precious stone, cut and polished for jewelry. They are all minerals. Some highly desirable gemstones may not be suitable for jewelry, yet be very collectible, like sphene. Others, like those in the corundum family, are prized for color and hardness, like emeralds and diamonds. Further, some common minerals, when polished, make beautiful pieces. With all that said, i woukd go with rarer.
True
Explanation:
Harry Hess in 1961 resurrected Wegener's continental drift hypothesis and also he mantle convection idea of Arthur Holmes by postulating the theory of sea floor spreading.
- After Wegener's postulation of the continental drift hypothesis, not much was done.
- It was only around 1931 that Arthur Holmes came up with the idea of a convecting mantle.
- After the second world war passed, new instruments were used to investigate and map the ocean floor.
- Through this, Arthur Holmes came up with the idea of a spreading sea floor.
- This gave a full gleam picture to the idea of a moving earth and the more accepted terminology of "Plate tectonics " came to the fore.
Learn more:
Sea floor spreading brainly.com/question/9912731
Continental drift brainly.com/question/5002949
#learnwithBrainly
Answer:
9
Explanation:
n-factor of NaOH = 1
OH⁻ concentration = Normality of NaOH
= Molarity x n-factor
= 10⁻⁵ x 1
= 10⁻⁵
Now, pOH = -㏒(OH⁻)
pOH = -㏒(10⁻⁵)
pOH = 5
We know pH + pOH = 14
pH = 14 - 5 = 9
∴pH of 10⁻⁵M NaOH is 9
Explanation:
A substance burning in the presence of oxygen and leads to the formation of heat and light is called combustion.
Some important points about combustion are as follows:
- Fuel should be present for burning.
- Air should be present for the supply of oxygen.
- There should be heat (or ignition temperature) to initiate the chemical reaction.
