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2 years ago

If boron atoms have 5 electrons, how many electrons are in the outer electron shell of a boron atom?

Chemistry

1 answer:

ANEK [815]2 years ago

3 0

Answer:

Explanation:

The first election shell can only hold 2 electrons, but the next one can hold up to 8

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What is the name of the binary molecule H2O2? This compound is also known as hydrogen peroxide and is a properly disinfectant or

Masteriza [31]

Answer:

hydrogen dioxide

Explanation:

3 0

3 years ago

By studying the distribution of different types of fossils, geologists have determined that some plates have traveled great dist

WITCHER [35]

Answer:

A. Fossils of organisms that lived in warm climates have been found in arctic environments.

Explanation:

One of the logic used by Geologists to justify plate movement over a region of space is that the fossils of organisms that lived in warm climates have been found in arctic environments.

this is as a result of plate tectonics.
organisms that are well adapted to warm climates in times past have their relics preserved as fossils.
their fossils are no found today around the arctic environment which are cold
this suggests that the plate must have drifted or moved

6 0

2 years ago

What is the mass of a sample of metal that is heated from 58.8°C to 88.9°C with a

Vadim26 [7]

Answer:

$\boxed {\boxed {\sf 333 \ grams}}$

Explanation:

We are asked to find the mass of a sample of metal. We are given temperatures, specific heat, and joules of heat, so we will use the following formula.

$Q= mc \Delta T$

The heat added is 4500.0 Joules. The mass of the sample is unknown. The specific heat is 0.4494 Joules per gram degree Celsius. The difference in temperature is found by subtracting the initial temperature from the final temperature.

ΔT= final temperature - initial temperature

The sample was heated <em>from </em> 58.8 degrees Celsius to 88.9 degrees Celsius.

ΔT= 88.9 °C - 58.8 °C = 30.1 °C

Now we know three variables:

Q= 4500.0 J
c= 0.4494 J/g°C
ΔT = 30.1 °C

Substitute these values into the formula.

$4500.0 \ J = m (0.4494 \ J/g \textdegree C)(30.1 \textdegree C)$

Multiply on the right side of the equation. The units of degrees Celsius cancel.

$4500.0 \ J = m (13.52694 J/g)$

We are solving for the mass, so we must isolate the variable m. It is being multiplied by 13.52694 Joules per gram. The inverse operation of multiplication is division, so we divide both sides by 13.52694 J/g

$\frac {4500.0 \ J }{13.52694 J/g}= \frac{m (13.52694 J/g)}{13.52694 J/g}$

The units of Joules cancel.

$\frac {4500.0 \ J }{13.52694 J/g}= m$

$332.6694729 \ g =m$

The original measurements have 5,4, and 3 significant figures. Our answer must have the least number or 3. For the number we found, that is the ones place. The 6 in the tenth place tells us to round the 2 up to a 3.

$333 \ g \approx m$

The mass of the sample of metal is approximately <u>333 grams.</u>

8 0

2 years ago

Explain why scientists find the particulate matter of theory useful

BARSIC [14]

This idea has historical significance. The ancient Greek philosopher Democritus (born 460 BCE), who held that everything is composed of small particles moving in empty space, is credited with developing the first hypothesis we have about the microscopic universe. He had some concrete proof for this, such the fact that items like a new loaf of bread or a rose may give off a scent even when they are far from the source. Being a materialist, he thought that these odors originated from actual material particles released by the bread or the rose, rather than being purely a type of magic. He reasoned that these particles must float through the air, with some of them maybe landing in your nose where you can smell them immediately. This still makes sense in modern times. But many of us now have quite different perspectives on these "particles."

Thank you,

Eddie

6 0

1 year ago

The pen on seismograph swings freely.

Sever21 [200]

This statment is false, the pen on a seismograph does not swing freely.

7 0

2 years ago