khurrambaig1997

Supply the term that describes each of the following changes of physical state:
a) solid to liquid
b) liquid to gas

Supply the term that describes each of the following changes of physical state:
a) gas to liquid
b) liquid to solid

Indicate whether the following changes of physical state require heating or cooling:
a) solid to liquid
b) gas to liquid

If two compounds have the same LD50(lethal dose 50) value, are they equally as toxic? Explain why or why not. Include a graph to illustrate your point and explain what the graph is showing in your answer. 

Explain two reasons why knowing the LD50(lethal dose 50) value is not useful for someone working with a chemical in a lab or being exposed to a toxin? 

I need to collect information and to write a full description for the following components related to composite combination of “polyvinyl alcohol (PVA) and gelatin”topic and its role in “Skin tissue engineering applications/Wound healing”: as the following

Abstract –

Chemical structure and properties –

Common uses –

Mechanical properties –

Swelling and degradation properties –

Porosity –

Scaffold fabrication methods –

Advantages and disadvantages –

Conclusion –

References (in a separate page, no upper limit for citing references, use standard journal formatting for references) – 5 pts

Which physical state is described as having a fixed shape and fixed volume?

Classify each of the following as an element, compound, homogeneous mixture, or heterogeneous mixture:

a) silver ingot
b) silver ore
c) silver oxide
d) silver alloy

CHEMISTRY - TOPIC: Electronic Configuration

QUESTION: An element has the following electronic configuration: [Kr]4d¹⁰5s²5p⁴ Answer the following:

(i) What period does it belong to?

(ii) What is its group number? (Use group numbers from 1 to 18)

(iii) What kind of element is it? (Main group metal, transition metal, metalloid, nonmetal?)

(iv) How many unpaired electrons are there in an atom of this element?

for each of the following elements, give the chemical symbol.atomic number and group number. Indicate whether the element is ametal, a nonmetal or a metalloid.

i) nitrogen ii) antimony iii) xenon

iv) strontium v) lithium

Write the chemical symbol for each of the following elements:

a) strontium
b) xenon
c) oxygen
d) zinc
e) fluorine
f) sodium
g) copper
h) nickel

In Python we also have functions for common tasks such as printing messages, receiving input , and so on. Mosh has created a cheat sheet with summary notes to review the materials in this course.