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3 years ago

Which is a FALSE statement about elements?

Chemistry

2 answers:

svetlana [45]3 years ago

6 0

C. Not each element has a known neutron number

OlgaM077 [116]3 years ago

3 0

Answer:

Option c, Each element has its own neutron number

Explanation:

Atomic number of any element is unique. All the atoms of an element have the same atomic number. Atomic number defines the identity of the element.

Atomic number is equal to number of proton. So, number of proton is also unique or each element has its own number of proton.

Chemical symbols are used to represent element in easiest way. Therefore, chemical symbol has to be specific for each element.

Atoms of an element can have different number of neutrons. Atoms of an element having same no. of proton but different no. of neutron are called isotopes.

So, among the given option, option c is false.

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Deploying an airbag in an automobile is a complex process. Identify at least three steps in the process. Refer to your research

gavmur [86]

Answer:

1) The car must have an accelerometer and airbag circut.

2) Chemical explosive of enough sodium azide to fill the bag when ignited

3) Airbag can be covered in talcum powder to help it unwrap smoothly.

Explanation:

8 0

3 years ago

Write the balanced dissociation equation for solid sulfur difluoride in aqueous solution. If it does not dissociate, simply writ

mojhsa [17]

Answer:

SF2(aq) → S²⁺(aq) + 2F-(aq)

Explanation:

The sulfur difluoride, SF2, dissolves in water because the differences in electronegativities are considerable (3.98 for Fluorine and 2.58 for S) doing the F-S bond polar. As water is a polar solvent will dissolve the SF2 as follows:

<em>As Fluorine has a > electronegativity than S, the Fluorine will be negative and S will be positive. Also, all halogen ions has a charge of -1.</em>

3 0

3 years ago

A certain ore is 33.0% nickel by mass. How many kilograms of this ore would you need to dig up to have 25.0 g of nickel?

Hoochie [10]

25/x=33/100
2500=33x
X=75.75757575757576grams

4 0

4 years ago

For the reactions below, describe the reactor system and conditions you suggest to maximize the selectivity to make the desired

alexandr1967 [171]

Answer:

hello your question lacks the required reaction pairs below are the missing pairs

Reaction system 1 :

A + B ⇒ D $-r_{1A} = 10exp[-8000K/T]C_{A}C_{B}$

A + B ⇒ U $-r_{2a} = 100exp(-1000K/T)C_{A} ^\frac{1}{2}C_{B} ^\frac{3}{2}$

Reaction system 2

A + B ⇒ D $-r_{1A} = 10exp( -1000K/T)C_{A}C_{B}$

B + D ⇒ U $-r_{2B} = 10^9exp(-10000 K/T) C_{B}C_{D}$

Answer : reaction 1 : description of the reactor system : The desired reaction which is the first reaction possess a higher activation energy and higher temperature is required to kickstart reaction 1

condition to maximize selectivity : To maximize selectivity the concentration of reaction 1 should be higher than that of reaction 2

reaction 2 :

description of reactor system : The desired reaction i.e. reaction 1 has a lower activation energy and lower temperatures is required to kickstart reaction 1

condition to maximize selectivity:

to increase selectivity the concentration of D should be minimal

Explanation:

Reaction system 1 :

A + B ⇒ D $-r_{1A} = 10exp[-8000K/T]C_{A}C_{B}$

A + B ⇒ U $-r_{2a} = 100exp(-1000K/T)C_{A} ^\frac{1}{2}C_{B} ^\frac{3}{2}$

the selectivity of D is represented using the relationship below

$S_{DU} = \frac{-r1A}{-r2A}$

hence SDu = 1/10 * $\frac{exp(-800K/T)}{exp(-1000K/T)} * C_{A} ^{0.5} C_{B} ^{-0.5}$

description of the reactor system : The desired reaction which is the first reaction possess a higher activation energy and higher temperature is required to kickstart reaction 1

condition to maximize selectivity : To maximize selectivity the concentration of reaction 1 should be higher than that of reaction 2

Reaction system 2

A + B ⇒ D $-r_{1A} = 10exp( -1000K/T)C_{A}C_{B}$

B + D ⇒ U $-r_{2B} = 10^9exp(-10000 K/T) C_{B}C_{D}$

selectivity of D

$S_{DU} = \frac{-r1A}{-r2A}$

hence Sdu = $1/10^7 * \frac{exp(-1000K/T)}{exp(-10000K/T)} *\frac{C_{A} }{C_{D} }$

description of reactor system : The desired reaction i.e. reaction 1 has a lower activation energy and lower temperatures is required to kickstart reaction 1

condition to maximize selectivity:

to increase selectivity the concentration of D should be minimal

3 0

4 years ago

What happens to a reducing agent during a redox reaction?

Nuetrik [128]

Reducing agent is an compound/atom, that loses an electron and is oxidized.

0.........+I.............+II............0
Ca + 2HCl ----> CaCl₂ + H₂

Calcium is oxidized --- it's reducing agent (reductant).
Hydrogen is reduced --- HCl is oxidizing agent.

7 0

3 years ago