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2 years ago

Matt's cube, after 5 trials, had an average density of 7.40 g/cm3 . His group's cube was made of

Chemistry

2 answers:

lawyer [7]2 years ago

5 0

its d zinc if your using usa test this dummy got me wrong trust me sis the answer is d

aleksandr82 [10.1K]2 years ago

4 0

The right answer for the question that is being asked and shown above is that: "B) gold." Matt's cube, after 5 trials, had an average density of 7.40 g/cm3 . His group's cube was made of <span>B) gold. </span>

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Silicon is an element that is found directly underneath carbon in the periodic table and thus has similar properties to carbon,

kirza4 [7]

Answer:

Four electrons are present in the valence shell of Silicon.

Explanation:

Valence shell electrons are those electrons which are present in the outermost shell of an atom. These valence shell electrons are responsible for in the formation of bonds with other atoms.

Silicon having atomic number 14 has fourteen electrons in its neutral state and has the electronic configuration as follow;

1s², 2s², 2p⁶, 3s², 3p²

In given configuration the valence shell (outermost shell) is 3 and the number of electrons present in it are four i.e. 3s² and 3p² (2 + 2 = 4) respectively.

7 0

3 years ago

An inverted pyramid is being filled with water at a constant rate of 45 cubic centimeters per second. The pyramid, at the top, h

vaieri [72.5K]

Answer:

13.20 cm/s is the rate at which the water level is rising when the water level is 4 cm.

Explanation:

Length of the base = l

Width of the base = w

Height of the pyramid = h

Volume of the pyramid = $V=\frac{1}{3}lwh$

We have:

Rate at which water is filled in cube = $\frac{dV}{dt}= 45 cm^3/s$

Square based pyramid:

l = 6 cm, w = 6 cm, h = 13 cm

Volume of the square based pyramid = V

$V=\frac{1}{3}\times l^2\times h$

$\frac{l}{h}=\frac{6}{13}$

$l=\frac{6h}{13}$

$V=\frac{1}{3}\times (\frac{6h}{13})^2\times h$

$V=\frac{12}{169}h^3$

Differentiating V with respect to dt:

$\frac{dV}{dt}=\frac{d(\frac{12}{169}h^3)}{dt}$

$\frac{dV}{dt}=3\times \frac{12}{169}h^2\times \frac{dh}{dt}$

$45 cm^3/s=3\times \frac{12}{169}h^2\times \frac{dh}{dt}$

$\frac{dh}{dt}=\frac{45 cm^3/s\times 169}{3\times 12\times h^2}$

Putting, h = 4 cm

$\frac{dh}{dt}=\frac{45 cm^3/s\times 169}{3\times 12\times (4 cm)^2}$

$=13.20 cm/s$

13.20 cm/s is the rate at which the water level is rising when the water level is 4 cm.

3 0

3 years ago

What is the difference between a physical and chemical change? From what I know a chemical change modifies the atoms of an objec

blsea [12.9K]

Physical change: a change in which no new substances are formed. the form of the substance is changed but not it's chemical composition (ice melting, bread toasting)

chemical change: any change that results in the formation of new chemical substances. this type of change modifies molecules and atoms by making and breaking the bonds between atoms! (iron rusting, gas burning)

so basically a physical change just changes the appearance of a substance, but a chemical change changes the makeup on a molecular level. i hope this helps you out!

6 0

2 years ago

What is the name of the ionic compound RbCI?

zloy xaker [14]

Answer:A

Explanation:taking the test now

5 0

3 years ago

How many grams of magnesium metal will react completely with 5.2 liters of 4.0 M HCl? Show all of the work needed to solve this

N76 [4]

Answer:
mass = 242.372 grams

Explanation:
1- getting the number of moles of HCl:
molarity = number of moles of solute / liters of solution
4 = number of moles of HCl / 5.2
number of moles of HCl = 4 * 5.2 = 20.8 moles

2- getting the number moles of magnesium:
From the balanced equation given, we can note that one mole of magnesium is required to react with two moles of HCl. To get the number of moles required to react with 20.8 moles of HCl. we will simply do cross multiplication as follows:
1 mole of Mg ...............> 2 moles of HCl
?? moles of Mg ...........> 20.8 moles of HCl
Number of moles of Mg = 20.8 / 2 = 10.4 moles

3- getting the mass of Mg:
number of moles = mass / molar mass
Using the periodic table, we can find that the molar mass of magnesium is 24.305 grams.
This means that:
10.4 = mass / 24.305
mass = 24.305 * 10.4
mass = 242.372 grams

Hope this helps :)

3 0

2 years ago