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3 years ago

The number of significant figures in 0.000820 g is?

1 answer:

7 0

There are 3 sig figs. 8 and 2 are obvious. The ending 0 is significant because it is at the end of a decimal number, and doesn't have to be measured.

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How many liters of carbon dioxide will be produced when 89.5 L of ethane are burned? (One mole of any gas occupies 22.4 L under

yan [13]

Answer:

179 L of CO2

Explanation:

Given the equation of the reaction;

C2H6(g) + 7/2 O2(g) -------> 2CO2(g) + 3H2O(g)

Now 1 mole of ethane yields 2 moles of CO2 from the balanced reaction equation

1 mole of a gas occupies 22.4 L volume so,

22.4 L of ethane yields 44.8 L of CO2

89.5 L of ethane yields 89.5 * 44.8/22.4 = 179 L of CO2

4 0

2 years ago

1. Alexa and her family travelled 5 hours south east on 1-45 to crystal

Gre4nikov [31]

Answer:

Average speed = 68 mph

Explanation:

Given that,

Total distance traveled by the family, d = 340 miles

The family traveled 5 hours southeast.

We need to find her average speed. The speed of an object is given by the total distance covered divided by time taken. So,

$v=\dfrac{d}{t}$

Put all the values,

$v=\dfrac{340}{5}\\\\v=68\ mph$

So, her average speed is equal to 68 mph.

5 0

2 years ago

An ion with 11 protons 12 neutrons and a charge of + 1 has an atomic number of

posledela

Answer:

11 electrons total and 23amu

Explanation:

This tells us that sodium has 11 protons and because it is neutral it has 11 electrons. The mass number of an element tells us the number of protons AND neutrons in an atom (the two particles that have a measurable mass). Sodium has a mass number of 23amu.

5 0

2 years ago

A meteor falls toward Earth's surface. Given that the acceleration due to

ICE Princess25 [194]

Answer:

E = 147000 J

Explanation:

Given that,

The mass of meteor, m = 50 kg

The altitude of the meteor, h = 300 m

We need to find the potential energy of the meteor. The formula for the potential energy is given by :

$E=mgh$

Put all the values,

$E=50\times 9.8\times 300\\\\E=147000\ J$

So, the required potential energy is equal to 147000 J.

4 0

3 years ago

: An unknown metal crystallizes in the cubic crystal structure. The metal has a radius 140pm, atomic mass of 135 g/mol, and dens

ki77a [65]

The cubic unit cell this metal crystallize as is BCC structure .

The structure of a crystalline solid, whether a metal or not, is best described by considering its simplest repeating unit, which is referred to as its unit cell.

The unit cell consists of lattice points that represent the locations of atoms or ions.

The entire structure then consists of this unit cell repeating in three dimensions

$\rm \rho =\dfrac{nM}{N_{0} a^{3}} \\\\\\\\\rm n =\dfrac{\rho N_{0} a^{3}}{M} \\\\\\\\Assuming\; it \; to \; be \; a\; BCC\; structure \\\\\\ r = \dfrac{\sqrt{3} \times a}{4} \\\\\\Therefore\; a = 3.23 \times 10^{-8}\\\\\\\\\rm n =\dfrac{13.3 \times 6.022 \times 10^{23}\times 3.23^{3}\times (10^{-8})^{3}}{135} \\\\$

n= 2

Hence our assumption was correct

It is a BCC structure .

Therefore the cubic unit cell this metal crystallize as is BCC structure .

To know more about unit cell

brainly.com/question/13110055

#SPJ1

5 0

2 years ago