Answer:
A. Compounds
Explanation:
Firstly, don't let the word "pure" confuse you; this is pretty much irrelevant to the question.
The key to answering this question lies in "substance" and "more than one type of element chemically bonded."
Something you ought to memorize is that a substance is either an element or compound. Therefore, you can eliminate choices B./C.
Next, use the part of the definition that says "more than one type of element chemically bonded" to conclude that it's a compound. Not only is this the definition of a compound, but the fact that is says <em>more than one type of element</em> should automatically tell you that it is different from just a regular element (Choice D.).
Answer:
a,d,e
Explanation:
its a,d, and e because clean air keeps us alive and other organisms need it to stay alive
Solution :
Given :
Amount of anserine solution = 0.200 M
pH value is = 7.20
Preparation of 0.04 M solution of anserine from the 0.2 M solution.
0.2 M x 
= 0.04 M x 1000 ml
= 200 ml
So the 200 ml of 0.2 M anserine solution is required to prepare0.04 M of anserine.
0.1 M x = 0.04 x 1000 ml
= 400 ml
Therefore, 400 ml of HCl is needed.
Answer:
The plastic bottle represents the chest cavity, the straws act as the bronchi, the small balloons inside the plastic bottle serves as the lungs and the big balloon at the bottom of the plastic bottle is the diaphragm.
Explanation:
OP already did it - CONGRATS!!
here are the steps 2 get the same ans:
(NH4)2 CO3 has 2x N, 8x H, 1x C and 3x O per molecule
so its molecular mass = 2x14 + 8x1 + 1x12 + 3x16
=28+8+12+48
=96g
of that 96g, 8x1=8g is due to Hydrogen
so by ratio n proportion, 1.00g will have 1x8/96 = 1/12g = 0.083g of H
