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Why is the streak plate preferred over the spot inoculations in the blood agar test?
The streak plate method allows for isolation of individual colonies from a mixed culture, providing pure cultures for further analysis. This helps in identifying specific pathogens more accurately compared to spot inoculations, which may not allow for such isolation and can lead to difficulty in distinguishing different organism colonies on the plate.
How do you determine the streak of a mineral whose Mohs scale is higher than the streak plate?
You can determine the streak of a mineral whose Mohs scale is higher than the streak plate by either filing or crushing with a hammer before rubbing the sample on a streak plate.
Which minerals on the Mohs scale will not leave a streak on the streak plate?
Diamond, corundum, and hematite are three minerals on the Mohs hardness scale that will not leave a streak on the streak plate because they are harder than the streak plate itself.
Can all minerals produce a streak on a porcelain plate?
Those minerals that are harder than the unglazed porcelain streak plate will scratch it rather than leave a streak.
When you rub a pumice rock on a streak plate what color is left on the streak plate?
The streak left on the streak plate by rubbing a pumice rock usually appears white or colorless. This is because pumice is a light-colored rock composed of volcanic glass with a frothy texture due to gas bubbles trapped in the rock, causing it to create a light streak when rubbed on a streak plate.
Why is the streak plate preferred over the spot inoculations in the blood agar test?
The streak plate method allows for isolation of individual colonies from a mixed culture, providing pure cultures for further analysis. This helps in identifying specific pathogens more accurately compared to spot inoculations, which may not allow for such isolation and can lead to difficulty in distinguishing different organism colonies on the plate.
What is the purpose of the plate?
A streak plate is used to determine the streak colour of a mineral. You take the mineral and scratch it against the streak plate, and it will create a coloured streak on the plate. The streak is not always the same colour as the mineral itself.
What happens if you rub the mineral across a streak plate but the mineral does not leave a streak?
The lack of a streak would indicate that the mineral is harder than the streak plate, or the color of the streak is the same as the color of the streak plate.
Will diamond leave a streak on a streak plate?
Diamond will not leave a streak on a porcelain streak plate because diamond is harder than the streak plate. It will leave a scratch on the streak plate for the same reason.
Can you show me a picture of a streak plate that has a streak from aquamarine on it?
I do not have a picture, but when you scratch aquamarine on a streak plate, the powder will be white colored.
What are 2 minerals that don't leave a streak on a streak plate?
Two minerals that do not leave a streak on a streak plate are quartz and fluorite. Both minerals have a hardness higher than that of the streak plate, so they will not leave a streak when rubbed against it.
What is scratching a mineral against a glass plate and rubbing a mineral on a streak plate helpful procedure for determining in a mineral?
Scratching a mineral against a glass plate helps determine the mineral's hardness based on the scratches produced. Rubbing a mineral on a streak plate helps identify the color of the mineral's streak, which can be different from its outer color due to impurities or weathering. These procedures are commonly used in mineral identification.
How do you determine the streak of a mineral whose Mohs scale is higher than the streak plate?
You can determine the streak of a mineral whose Mohs scale is higher than the streak plate by either filing or crushing with a hammer before rubbing the sample on a streak plate.
What is the powder left behind on a streak plate called?
The powder left behind on a streak plate is called a streak. It is produced by scraping a mineral sample across the plate to reveal its color and texture. This streak can be compared to a mineral's known streak color to help with identification.
Why doesn't the mineral topaz leave a streak on a streak plate?
It leaves a scratch instead of a streak because Topaz has a higher number on the Moh's scale compared to the streak plate.
Which minerals on the Mohs scale will not leave a streak on the streak plate?
Diamond, corundum, and hematite are three minerals on the Mohs hardness scale that will not leave a streak on the streak plate because they are harder than the streak plate itself.
What mineral will scratch glass but not a streak plate?
Diamond is the only mineral that can scratch glass but not leave a streak on a streak plate. Glass has a hardness of around 5.5 on the Mohs scale, while a streak plate typically has a hardness of around 6.5. Diamond, with a hardness of 10, is able to scratch glass but not the streak plate.
