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NISA [10]
2 years ago
12

A scientist is performing an experiment on a powder. Which of the following is a sign that a chemical change has definitely occu

rred during his experiment?
The powder catches on fire.
The powder releases bubbles.
The powder heats up.
The powder breaks apart into smaller particles.
Chemistry
1 answer:
n200080 [17]2 years ago
7 0
The powder catches fire. The rest of the choices pertains to physical changes on the powder. When the powder catches fire a chemical change happens. For example, if the powder is organic, carbon dioxide and water will result during the combustion. 
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What is the difference between Mixtures and Compounds? I am trying to study for my Science quiz on Tuesday, and I need to know t
Deffense [45]
A mixture can be separated.  Everything in a mixture keeps it's own properties and are not chemically joined together.  I am not completely sure about the compound.  Although with the cake example, the ingredients have been mixed and kind of "fused" together upon baking. Hope this helps a little. (P.S. trail mix is a good example of a mixture.)
8 0
2 years ago
Chemists can use moles to calculate: A. How much of the products are needed and how much reactant will be made. B. How much prod
damaskus [11]

Answer:

c.- How much of the reactants are needed and how much product will made.

Explanation:

The moles is the matter unit used in chemistry to simplify  some calculations, instead of using grams. Also the moles are very useful because the chemical reaction can be balanced.

When a Chemical reaction is balanced, then it can be easily to calculate how many moles are necessary to add in a process to obtain a quantity of grams of a product.

5 0
3 years ago
An ______ cannot be broken down into any other substance
QveST [7]

Answer:

an atom cannot be broken down

6 0
2 years ago
Read 2 more answers
Which part of the periodic would contain an element with a partially filled f sublevel
noname [10]

Answer: Lanthanide and actinide series

Explanation: The elements with partially or fully filled f orbitals belong to f block elements.

f block elements include lanthanides and actinides. They are called so the lanthanides contain the first element named as lanthanum and actinides contain first element named as actinium. They are also called as inner transition elements.

All of them have general electronic configuration:

(n-2)f^{1-14}(n-1)d^{0-10}ns^2, where n = 6-7

8 0
3 years ago
Read 2 more answers
What is the pressure of 1.50 moles of a gas in a 30.0L tank at a temperature of<br> 285K?
julia-pushkina [17]

The pressure of the gas : 1.1685 atm

<h3>Further explanation</h3>

In general, the gas equation can be written  

\large {\boxed {\bold {PV = nRT}}}

where  

P = pressure, atm  

V = volume, liter  

n = number of moles  

R = gas constant = 0.08206 L.atm / mol K  

T = temperature, Kelvin  

n=moles=1.5

V=volumes = 30 L

T=temperature=285 K

The pressure :

\tt P=\dfrac{nRT}{V}\\\\n=\dfrac{1.5\times 0.082\times 285}{30}\\\\P=1.1685~atm

7 0
2 years ago
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