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Mnenie [13.5K]
3 years ago
7

Hannah does an experiment. She has two colorless chemicals that she mixes together in a beaker. Which of the following indicates

that a chemical change occurs when she mixes the two chemicals together?
I. The chemicals change color from colorless to purple.
II. A yellow gas forms.
III. A brown solid forms in the bottom of the beaker.
IV. The temperature of the chemicals rises 15°C.
Chemistry
2 answers:
uranmaximum [27]3 years ago
8 0
I am not to sure but is it all 4 of them?
alexandr402 [8]3 years ago
6 0

The answer is all 4 of them


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5. If a block of wood has a density of 0.6 g/cm3 and a mass of 120 g, what is its volume? (D= M/V)
AlexFokin [52]

Answer:

200 cm^3

Explanation:

V = M/D

V = 120g / (0.6g/cm^3)

V = 200 cm^3

4 0
3 years ago
Write a brief passage describing a neutral atom of
nasty-shy [4]

Answer:

Detail is given below.

Explanation:

Electron:

The electron is subatomic particle that revolve around outside the nucleus and has negligible mass. It has a negative charge.

Symbol= e-

Mass= 9.10938356×10-31 Kg

It was discovered by j. j. Thomson in 1897 during the study of cathode ray properties.

Neutron and proton:

While neutron and proton are present inside the nucleus. Proton has positive charge while neutron is electrically neutral. Proton is discovered by Rutherford while neutron is discovered by James Chadwick in 1932.

Symbol of proton= P+  

Symbol of neutron= n0  

Mass of proton=1.672623×10-27 Kg

Mass of neutron=1.674929×10-27 Kg

Location of electron, proton and neutron.

An atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.

All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example if neutral atom of nitrogen have 7 protons than it must have 7 electrons. The sum of neutrons and protons is the mass number of an atom while the number of protons are number of electrons is the atomic number of an atom.

For example

Mass of nitrogen = number of neutron + number of proton

Mass of nitrogen = 7 + 7 = 14

Atomic number of nitrogen = number of electron or number of proton

Atomic number of nitrogen = 7

3 0
4 years ago
Read 2 more answers
Can somebody plz just answer this 1 question thx!!!
coldgirl [10]

Answer:

cetacean i think thats the answer

3 0
3 years ago
Charcoal is primarily carbon. what mass of co2 is produced if you burn enough carbon (in the form of charcoal) to produce 4.80 k
Reika [66]
When carbon is burned in air carbon iv oxide gas is formed.
C (s) + O2 (g) = CO2(g)  ΔH = - 393.5 kj/mol
The enthalpy change of the  reaction is -393.5 j/mol which means that when one mole of carbon is completely burnt in air then 393.5 j of energy is evolved.
Thus, 1 mole = -393.5 j , then for 480 kj 
            = 480 × 1/393.5
             = 1.2198 moles
          1 mole of carbon iv oxide is equal to 44 g 
thus, 1.2198 moles will be 1.2198 × 44 = 53.6712 g of CO2
6 0
4 years ago
How many moles are in 175g<br> (Ca(NO3)2
zheka24 [161]

Answer:

appx. 1.07 moles

Explanation:

175g of molecule Ca(NO3)2

To find the # of moles, use stoichoimetry.

1. We need the molar mass of Ca(NO3)2.

Ca mass: 40.08 g

NO3 mass: N + 3(O) --> 14.01 + 3(16.00) --> 62.01

Molar mass = Ca + 2(NO3) --> 40.08 + 2(62.01) --> 164.1 g

2. write out the calculation

175g Ca(NO3)2 * (1 mole Ca(NO3)2)/(molar mass of Ca(NO3)2)

175 g Ca(NO3)2 * (1 mole Ca(NO3)2)/(164.1 g Ca(NO3)2)

The g units cancel out and we're left with moles.

Simply perform the calculation now: 175*1/164.1 ≅1.07 moles

6 0
3 years ago
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