How to align image within nested div<> with spaces in div names - css

Question

I have nested div elements with image in one of nested div on my page layout. I want to write CSS style for align image to right. How I do that:
I actually want to know how i access nested div <div id="Imagepart1" class="new1 new1-50 adjust-right"> for writing CSS style in order to align image to right. This is how div within divs looks like:
<div id="Testcase1" class="item1 module">
<div id="Div1" class="new-block">
<div id="Imagepart1" class="new1 new1-50 adjust-right">
<div class="new-gutter">
<div>
<img alt src="/sitecollectioImages/MyWork/exampleimage.png">
</div>
</div>
</div>
</div>
</div>

Answer 1

It all depends on the specificity required to apply your style. You have a few options:
.adjust-right { float: right; } might be enough, this has a
specificity of 0,0,1,0.
You could also use multiple classes to target the DIV,
.item1.adjust-right { float: right; }, this has a specificity of 0,0,2,0.
If not enough you can hook into the id attribute, #Imagepart1 { float: right; }, this has a specificity of 0,1,0,0.
More on specificity here.
It is preferred to style via options 1 and 2 and leave IDs as JS hooks.
Update
OP asked about using multiple CSS classes in the selector and what the difference is when leaving a space between the classes and not.
When there IS NOT a space between CSS classes in the CSS selector then all those classes must be present on an element for the selector to match. Without a space you are saying find class X, then see if class Y appears on the same element as class X.
If there IS a space between CSS classes in the CSS selector then you are targeting items that are nested. With each space you are saying (from left to right) find class X, then any element inside of element with class X find an element with class Y.
<!-- #1 -->
<div class="outer right">
<!-- #2 -->
<div class="inner left">
<!-- #3 -->
<div class="core right"></div>
</div>
</div>
Given the above markup the following selectors will:
.outer.right, NO SPACE, selects the outer most DIV (#1). Requires that BOTH the .outer and .right class appear on the same element (order does not matter).
.outer .right, WITH SPACE, selects the inner most DIV (#3). Requires that .right appear on an element somewhere inside of an element with .outer.

Answer 2

An 'id' can be accessed with the '#' symbol and classes can be accessed via the dot operator '.' http://www.w3schools.com/css/css_syntax.asp
So you can actually target the div you described with
#Imagepart1{
float: right
}
or accessing one of the classes attached to it
.adjust-right{
float: right
}
or explicit use of all the classes
.adjust-right.new.new1-50{
float: right;
}