ch.2

correct formula for barium hydride

BaH2

Write the empirical formula for caffeine (C8H10O2), a stimulant found in tea and coffee.

C4H5N2O

write the molecular formula of chloroform, which is used as a solvent and a cleansing agent. The structure of chloroform is shown in image

CHCl3

The ionic compound CrCI3 is correctly named

Chromium (III) Chloride.

What is the formula of the ionic compound formed from Li+ and Ne3-?

Li3N

Write the formula of the following ionic compounds. a) chromium(III) sulfate (containing the Cr3+ and SO42− ions) b) tin(IV) oxide (containing the Sn4+ and O2− ions) formula

a) Cr2(SO4)3 b) SnO2

In the solid form, the ionic compound NaBr consists of

altering ions in a three-dimensional lattice

basic unit of an element that can enter into chemical combination

atom

It is common to represent an element using its atomic symbol, which is an abbreviation based on its name. The _____ number, given the symbol z, is written as a left subscript while the ______ number, given the symbol A, is written as a left superscript next to the atomic symbol.

atomic; mass

The charged particle that forms when an atom, or small group of atoms, loses or gains one or more_____ is called an ion. An ion with a positive charge is called a(n) _________ while an ion with a negative charge is a (n) anions.

electrons ; cations ; anions

Which of the following statements about an atom represented by the symbol 79/35Br are correct?

- The atom has 35 electrons - The atom has an atomic number of 35

which of the following options correctly describe how to name an ionic compound

- for a monatomic anion, the element name is changed to end in -ide - the cation is named first and the anion second

which of the following statements correctly describes isotopes?

- isotopes have similar chemical properties - isotopes have different number of neutrons - isotope of the same element have the same element symbols

Which of the following statements describe the chemical formulas of ionic compounds correctly?

- the formula of ionic compound are usually empirical formulas - the sum of the charges of each ion that makes up an ionic compound must be zero

Match each formula with its correct name 1. NO - Nitrogen dioxide 2. NO2 - Dinitrogen trioxide 3.N2O - Nitrogen monoxide 4.N2O3 - Dinotrogen monoxide

1. NO - Nitrogen monoxide 2. NO2 - Nitrogen dioxide 3.N2O - Dinotrogen monoxide 4.N2O3 - Dinitrogen trioxide

A neutron has a mass of ____ amu (to the nearest whole number) and a charge of

1; 0

how many electrons in the ion 79/34Se2-

36 electrons Se gains two electrons to form Se2-

Which of the following isotopes contain 12 neutrons in their nucleus?

- 23/11 Na - 22/10 Ne

A particular isotope of an element is represented by the symbol 15/7N. Which of the following options correctly interpret this symbol?

- 7 neutrons - 8

Select all the formulas that correctly identify the most common form of each element at room temperature

- O2 - CI2

A compound of copper and sulfur contains 88.39 g of metal and 44.61 g of nonmetal. How many grams of copper are in 5264 kg of compound? How many grams of sulfur?

https://www.slader.com/discussion/question/a-compound-of-copper-and-sulfur-contains-8839-g-of-metal-and-4461-g-of-nonmetal-how-many-grams-of-co/

The ____ number of an atom is equal to the sum of the protons and ___. in the nucleus of the atom

mass; neutrons

periodic table groups

metals nonmetals metalloids

A molecular compound is electrically ____ and is composed of individual units called _____

neutral ; molecules

An atom is composed of a very dense central ______ containing _______, which are positively charged, and neutrons, which have _______ electric charge.

nucleus; protons; no