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3 years ago

Which spacecraft exploded during flight killing all astronauts?

2 answers:

7 0

In January 1986, five astronauts and 2 other passengers were killed when the spacecraft shuttle Challenger exploded shortly after its launch. It delayed more space exploration for about 32 months, I think.

Natasha_Volkova [10]3 years ago

4 0

On January 28, 1986, the NASA shuttle orbiter mission STS-51-L and the tenth flight of Space Shuttle Challenger (OV-99) broke apart 73 seconds into its flight, killing all seven crew members, which consisted of five NASA astronauts and two payload specialists.

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An atom gets over all positive charge by ____ _______

Rasek [7]

<h2>Answer:</h2>

Nucleus.

<h2>Explanation:</h2>

In an atom the nucleus has an overall positive charge as it contains the protons.
Every atom has no overall charge (neutral). While atoms do contain charged particles, they have the same number of positive protons as negative electrons( for example a sodium atom has 11 electrons which are of negative charge and 11 protons which are of positive charge).
These opposite charges cancel each other out making the atom neutral.

Result: Nucleus is the overall positive charge of an atom.

4 0

3 years ago

The path urine takes after it is formed until it leaves the body is the urethra, urinary bladder, and finally the ureter. True F

Vlad1618 [11]

Answer:

False

Explanation:

The urine is produced in the kidneys, each one of the kidneys is connected to a ureter. The ureter is a tube that propels the excreted urine to the urinary bladder. The urinary bladder is a deposit for the urine, here is collected and stored before disposal. After the urinary bladder, the urine goes through the urethra, which is a tube, to exit the body.

4 0

3 years ago

A compound is 2.00% H by mass, 32.7% S by mass, and 65.3% O by mass. What is its empirical

Katarina [22]

Answer:

empirical formula: $H_2SO_4$

2 g H

32.7 g S

65.3 g O

Explanation:

Like the problem said, the first thing we can do is calculate the mass of each of the 3 elements in a 100-gram sample:

- 2.00% * 100g = 2 g H

- 32.7% * 100g = 32.7 g S

- 65.3% * 100g = 65.3 g O

Now we need to find the empirical formula from these. To do so, convert all of those masses into moles by using the molar mass for each element:

- the molar mass of H is 1.01 g/mol

- the molar mass of S is 32.06 g/mol

- the molar mass of O is 16 g/mol

2 g H ÷ 1.01 g/mol = 1.98 mol H

32.7 g S ÷ 32.06 g/mol = 1.02 mol S

65.3 g O ÷ 16 g/mol = 4.08 mol O

Our ratio of H : S : O is now:

1.98 mol : 1.02 mol : 4.08 mol

Divide them all by the smallest number, which is 1.02:

1.98/1.02 : 1.02/1.02 : 4.08/1.02

1.94 : 1 : 4

1.94 ≈ 2

So:

2 : 1 : 4

Thus, the empirical formula is: $H_2SO_4$ .

7 0

3 years ago

3. What mass of copper could be deposited from a copper(II) Sulphate solution using a current of 5.0 A over 100 seconds? ( F =96

arsen [322]

Mass of copper : 0.165 g

<h3>Further explanation</h3>

Given

5.0 A over 100 seconds

Required

Mass of copper

Solution

Faraday's law:

<em>The mass of the substance formed at each electrode is proportional to the electric current flowing in the electrolysis</em>

<em /> $\tt W=\dfrac{e.i.t}{96500}$ <em />

e = Ar / valence = eqivalent weight

i = current

t = time

W = weight

CuSO₄ ----> Cu²⁺ + SO₄²⁻

Cu ----> Cu²⁺ + 2e

e = Ar/2

= 63,5/2 = 31,75

$\tt W=\dfrac{31.75\times 5\times 100}{96500}=0.165~g$

8 0

3 years ago

The heat required to raise the temperature of 12g of water from 16 C to 21 C is:

NemiM [27]

Answer:

The heat required to raise the temperature of 12g of water from 16 C to 21 C is 60 cal.

Explanation:

Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.

There is a direct proportional relationship between heat and temperature. The constant of proportionality depends on the substance that constitutes the body as on its mass, and is the product of the specific heat by the mass of the body. So, the equation that allows calculating heat exchanges is:

Q = c * m * ΔT

where Q is the heat exchanged by a body of mass m, made up of a specific heat substance c and where ΔT is the temperature variation.

In this case, you know:

Q=?
c= 4.186 $\frac{J}{g*C}$
m= 12 g
ΔT=Tfinal - Tinitial= 21 °C - 16°C= 5 °C

Replacing:

Q= 4.186 $\frac{J}{g*C}$ *12 g *5 °C

Solving:

Q=251.16 J

Since 1 J is equal to 0.2388 cal, then the following rule of three can be applied: if 1 J is equal to 0.2388 cal, then 251.16 J to how many cal are?

$cal=\frac{251.16 J * 0.2388 cal}{1 J}$

cal= 59.98 ≅ 60

<u><em>The heat required to raise the temperature of 12g of water from 16 C to 21 C is 60 cal.</em></u>

3 0

3 years ago