Animal cells do not have a cell wall or chloroplasts but plant cells do. Animal cells are mostly round and irregular in shape while plant cells have fixed, rectangular shapes.
948 or 9.48 x 10^2
There are two sets of rules for significant figures
• One set for addition and subtraction
• Another set for multiplication and division
You used the set for multiplication and division.
This problem involves addition and subtraction, and the rule is
The number of places after the decimal point in the answer must be <em>no greater than the number of decimal places in every term</em> in the sum.
Thus, we have
78.9
+890.43
-21.
= 948.33
The "21" term has the fewest digits after the decimal point (none), so the answer must have no digits after the decimal point.
To the correct answer is 948 = 9.48 x 10^2. It has three significant figures.
Answer:
Helium is the second element on the periodic table. It is located in period 1 and group 18 or 8A on the righthand side of the table. This group contains the noble gases, which are the most chemically inert elements on the periodic table. Each He atom has two protons and usually two neutrons and two electrons.
Explanation:
thoughtco.com
A compound<span> is a </span>molecule<span> that contains at least two different elements. </span>All compounds<span> are </span>molecules<span> but not </span>all molecules<span> are </span>compounds<span>. </span>Molecularhydrogen (H2<span>), </span>molecular<span> oxygen (O</span>2<span>) and </span>molecular<span> nitrogen (N</span>2) are notcompounds<span> because each is composed of a single element.</span>
Mg + Cl₂ = MgCl₂M(Mg) = 24г/моль m 1 моль Mg = 24 г.По условию задачи дано 12г. Mg Количество вещества n(Mg) =12÷24=0,5 мольРассуждаем: по уравнению реакции с 1 моль магния реагирует 1 моль хлора, следовательно с 0,5 моль будет реагировать 0,5 моль хлора.1 моль хлора при н.у. занимает объем 22,4л. , тогда 0,5 моль хлора займет:0,5х22,4л.= 11,2л. Ответ: Для взаимодействии 12 г. магния потребуется 11,2 л. хлора.
