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Neporo4naja [7]
3 years ago
7

I need help with these two questions

Chemistry
1 answer:
natulia [17]3 years ago
8 0
I'm not sure about 2 but in 3 it would float
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An airplane model is an example of what type of model
Ksju [112]
TL;DR: The make of an aircraft is the name of the designer (for example, Boeing) and the model of an aircraft (also called the type) is the designation for the general design of the aircraft (for example, 737). It looks like "basic model" is just an older term for "model".
7 0
3 years ago
A molecule made of hydrogen and carbon with Mr of 56 has the following composition: carbon 85.7%; hydrogen 14.3%. Calculate the
Veseljchak [2.6K]

Answer:

Assume that 100 grams of C2H4 is present. This means that there are 85.7 grams of carbon and 14.3 grams of hydrogen.

Convert these weights to moles of each element:

85.7 grams carbon/12 grams per mole = 7 moles of carbon.

14.3 grams hydrogen/1 gram per mole = 14 moles of hydrogen.

Divide by the lowest number of moles to obtain one mole of carbon and two moles of hydrogen.

Since we know that there cannot be a stable CH2 molecule, multiply by two and you have C2H4 which is ethylene - a known molecule.

The secret is to convert the percentages to moles and find the ration of the constituents.

5 0
2 years ago
True of false metals like copper are sometimes used to fill cavities in teeth
ElenaW [278]
I'd say false because copper is what they used to drink out of in the middle ages, and it caused them to get very sick, so I doubt they would use copper in your mouth.
7 0
3 years ago
Read 2 more answers
When a caterpillar is big enough, it will form a chrysalis. During which stage of metamorphosis does this occur? (2 points) a Ad
weqwewe [10]

Answer: The stage of metamorphosis this occurs is called the PUPA stage. The correct option is D.

Explanation:

Metamorphosis can be defined as the change in form, mode of life and behaviour that occurs during embryonic development of an organism. In the metamorphosis of insects, which mostly reproduce sexually, insects can be grouped according to the way the eggs develop into adults. Some show:

--> Complete metamorphosis or

--> Incomplete metamorphosis.

In the life cycle of a butterfly, a COMPLETE metamorphosis occurs. This is because after fertilization, the EGG hatches into LARVA which passes through a PUPAL stage before becoming transformed into an ADULT insect. That is:

Egg --> Larva --> Pupa --> Imago.

When the caterpillar, which is the Larva stage, has reached its full size, it spins a pad of silk on a twig. It moves upward and attached it's clasper to this pad. It spin another silk thread at the thorax. These aids it to assume a slanting position with the head end pointing upwards. The pupa stage called the CHRYSALIS is reached when it tucks it's head under its thorax, arches it's body, shortens and broadens, and moults for the last time. Therefore the correct option is D (pupa).

6 0
3 years ago
Read 2 more answers
A reaction vessel contains equal masses of iron and oxygen. How much FeO could theoretically be produced?
snow_tiger [21]

Answer:

c

Explanation:

6 0
3 years ago
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