A type of steel made from copper-alloyed steel that protects itself from corrosion is ______________

Can someone help.? thanks :)

laila [671]

Answer:

1. Equation: 2x + 3 = 9x - 11

2. Each row has 2 chairs

Explanation:

The variable x represents the number of chairs in each row.

1. She can form 2 rows of a given length with 3 chairs left over.

Thus, she has:

number of rows number of chairs in chairs number of chairs

each row left over she has

2 x 3 2x + 3

2. She can form 9 rows of the same length if she gets 11 more chairs.

That means that she is short in 11 chairs to have 9x chairs, or that she has 11 less chairs than 9x chairs. Then she has:

9x - 11

3. Equation:

Then, number of chairs she has is 2x + 3 and, also, 9x - 11, which allows to set the equation:

2x + 3 = 9x -11

4. Solve the equation:

9x - 2x = 3 + 11

7x = 14

x = 2

Therefore, each row has 2 chairs, and she has 2x + 3 = 4 + 3 = 7 chairs.

4 0

4 years ago

Suppose you wanted to make 100 grams of water. A. What is the molar mass of water (H2O)? B. How many moles of water are in 100 g

Gemiola [76]

I need to answer more

4 0

3 years ago

Read 2 more answers

Many monatomic ions are found in seawater, including the ions formed from the following list of elements. Write the Lewis symbol

77julia77 [94]

Answer:

The Lewis structures are in image attached.

Explanation:

Lewis symbol is a representation of an element symbol along with its valence electrons around it in the form of dot(s).

Mono-atomic ions formed from the following :

(a) Cl

Chlorine's atomic number is 17 in which only 7 electrons are present in its valence shell .So in order to gain noble gas stability it will gain 1 electron to completes its octet

$Cl=1s^22s^22p^63s^23p^5$

$Cl^-=1s^22s^22p^63s^23p^6$

(b) Na

Sodium's atomic number is 11 in which only 1 electrons are present in its valence shell .So in order to gain noble gas stability it will loose 1 electron to completes its octet. In the Lewis symbol no dot shown as sodium has lost its 1 electron.

$Na=1s^22s^23p^63s^1$

$Na^+=1s^22s^23p^63s^0$

(c) Mg

Magnesium's atomic number is 12 in which only 2 electrons are present in its valence shell .So, in order to gain noble gas stability it will loose 2 electrons to completes its octet.

In the Lewis symbol no dot shown as magnesium has lost its 2 electrons.

$Mg=1s^22s^23p^63s^2$

$Mg^{2+}=1s^22s^23p^63s^0$

(d)Ca

Calcium's atomic number is 20 in which only 2 electrons are present in its valence shell .So, in order to gain noble gas stability it will loose 2 electron to completes its octet.

In the Lewis symbol no dot shown as calcium has lost its 2 electron.

$Ca= 1s^22s^22p^63s^23p^64s^2$

$Ca^{2+}=1s^22s^23p^6^23p^64s^0$

(e) K

Potassium's atomic number is 19 in which only 1 electrons are present in its valence shell .So, in order to gain noble gas stability it will loose 1 electron to completes its octet.

In the Lewis symbol no dot shown as calcium has lost its 1 electron.

$K= 1s^22s^22p^63s^23p^64s^1$

$K^{+}=1s^22s^23p^6^23p^64s^0$

(f) Br

Bromine's atomic number is 35 in which only 7 electrons are present in its valence shell .So in order to gain noble gas stability it will gain 1 electron to completes its octet

$Br=1s^22s^22p^63s^23p^63d^{10}4s^24p^5$

$Br^-= 1s^22s^22p^63s^23p^63d^{10}4s^24p^6$

(g) Sr

Strontium's atomic number is 38 in which only 2 electrons are present in its valence shell .So, in order to gain noble gas stability it will loose 2 electron to completes its octet.

In the Lewis symbol no dot shown as calcium has lost its 2 electron.

$Sr=1s^22s^22p^63s^23p^63d^{10}4s^24p^65s^2$

$Sr^{2+}=1s^22s^22p^63s^23p^63d^{10}4s^24p^65s^0$

(h) F

Florine's atomic number is 7 in which only 7 electrons are present in its valence shell .So in order to gain noble gas stability it will gain 1 electron to completes its octet.

$F=1s^22s^22p^5$

$F^-=1s^22s^22p^6$

5 0

3 years ago

Oxygen has 6 valence electrons. how many hydrogen atoms (who have 1 valence electrons) can bond with it? remember the octet rule

Stella [2.4K]

Answer:

two hydrogen can bonded with oxygen to form H2O

5 0

3 years ago

A salt is known to be an alkali metal fluoride. A quick approximate determination of freezing point indicates that 4 g of the sa

nexus9112 [7]

For the answer to the question above, I can't help you directly because I don't have a calculator right now. But I'll show you how to solve this.
use the freezing point depression formula for this one: delta T = i * m * K where K is a constant, m is the molality (mol solute/kg solvent), and i is the van'hoff factor the van hoff factor is the number of ions that your salt dissociates into. Since it's an ALKALI flouride salt, how many ions? k is just a constant, you get it from a table in your textbook somewhere So you have everything to solve for the molality of the solution, once you did that, multiplying it by the mass of water to find the mols of the salt. Take the mass of the salt and divide by this mols to figure out the molar mass, and then compare it with the periodic table to identify the salt.

Mole solute x mass of Water = Mol solute
kg Solvent

then

Mass of solute x 1 = molar mass
mole of solute

4 0

3 years ago

Read 2 more answers

A type of steel made from copper-alloyed steel that protects itself from corrosion is _______________ steel.